Articulation and occlusion. Biomechanics of movement of the mandible (Vertical, sagittal, transversal movements of the mandible). Methods of investigation of orthopedic patients.
Articulation is every possible positions and movings of the mandible in relation to the maxilla carried out by means of chewing muscles (A.Ya.Katts). Of greatest practical value is moving of the mandible in chewing.
Occlusion is any joining of the teeth, a special case of articulation (A.Ya.Katts). The number of occlusion is great. The most important of them in practice are fourocclusions: centralocclusion, anterior and two lateral (left and right) occlusions.
It is clear that occlusion being clinical expression of the chewing movements, breaks up into separate phases according to kinds of the chewing movements. The chewing movements of the mandible as well as its general movements, are divided into sagittal, transversal and vertical. In this connection occlusion phases or phases of the dentitions should also be divided into sagittal (anteroposterior), transversal (lateral) and vertical (central). It coincides with division of the chewing process into three phases:
1) a phase of gripping and cutting of food which is characterized by sliding of the cutting edges of the lower anterior teeth along the palatine surfaces upward to their regional joining and backward; sagittal movement prevails in this phase and, hence, sagittalocclusion;
2)the phase of food crushing which is carried out by the vertical movement of the mandible and characterized by the maximal contact of the teeth of both jaws; occlusion of dentitions in this phase has received the name of central and is the initial and final moment of all chewing movements of the mandible;
3) a phase of grinding food which is characterized by alternating movings of the mandible to the sides. In movement of the mandible in any side the tubers of the masticatory teeth of the mandible will contact with same tubers of the maxilla (buccal with buccal, palatal with lingual) on this side.
The word “articulation” is derived from anatomy where it designates a joint, articulation, however many authors give different meaning to this word. In our dentistry the definition of this term given by A.J.Kats is of the greatest use – articulation is every possible positions and movings of the mandible in relation to the maxilla carried out by means of the chewing muscles.
This definition of articulation includes not only chewing movement of the mandiblebut also its movement during conversation, yawning, etc. For practical purposes it is most convenient to define articulation as a chain of variants of occlusion replacing each other. Such definition is more concrete, i.e. covers only chewing movements of the mandiblewhich studying is very important for construction of special devices reproducing them – articulators.
Occlusion is joining of dentitions on the whole or by separate groups of the teeth during a greater or smaller interval of time.
Thus, occlusion is considered to be a special case of articulation, one of its moments.
Four basic kinds of occlusion are distinguished: central, anterior and lateral (right and left).
Central occlusion is characterized by joining teeth at a maximum quantity of contacting points
Signs of central occlusion:
– the midline of the face coincides with a line passing between the central incisors;
– articular heads are located on the slope of the articular tubercle at its basis.
Central occlusion
The front view and side view.
There is simultaneous and uniform contraction of the masticatory and temporal muscles on either side.
In the anterior occlusion there is a moving out of the mandibleforward. It is achieved by bilateral contraction of the lateral pterygoid muscles.
Signs of anterior occlusion:
– The midline of the face coincides with the midline which passes between the incisors;
– The articular heads in anterior occlusion are displaced forward and located at the top of the articular tubercles.
Lateral occlusion arises in moving of the mandibleto the right (right occlusion) or to the left (left occlusion)
Signs of lateral occlusion:
– in displacement of the mandible to the right the articular head remains at the basis of articular tubercle on the side of displacement, slightly rotating. On the left side the articular head is located at the top of the articulate tubercle;
– right lateral occlusion is accompanied by contraction of the lateral pterygoid muscles of the opposite (left) side and, on the contrary, left lateral occlusion – contraction of the same muscle of the right side.
Condition of relative rest of the mandible.
If there is no chewing and talking dentition are usually opened, i.e. the mandiblehangs and a lumen of 1-6 mm in size is observed between frontal teeth. In dropping of the jaw the muscle are a little stretched that causes irritation of the proprioceptors.
It necessitates tonic contraction of the muscles which keeps the jaw in the specified position. Various groups of fibres are alternatively contracted in the masticatory muscles that provides rest and at the same time allows to be ready to new contraction. Energy expenses of the muscles under the condition of relative physiological rest are minimal. The width of the lumen between the central incisors in position of rest of the mandibleis individually various. There are data that it increases with the years. Besides the position of relative rest of the mandibleis an expedient reflex act (an alternating masticatory pressure is physiological for the periodontium whereas constant rest would cause its ischemia and development of dystrophy).
Position of the rest of the mandibleis a protective congenital reflex. It is initial and final for all its movements.
BIOMECHANICS OF THE MANDIBLE
Biomechanics is a science about movements of the person and animals. It studies movements from the point of view of the laws of mechanics peculiar to all mechanical movements of the material bodies without exception. Biomechanics investigates the objective laws revealed during research. Their knowledge allows to expect results of practical activities, assisting in conduction it systematically counting upon the certain result.
Studying of movements of the mandibleallows to receive representation about their norm as well as to reveal impairments and their influence on activity of the muscles, joints, teeth occlusion and condition of the parodont. The mandibleparticipates in many functions: chewing, speech, swallowing, laughter, etc. but its masticatory movements are of greatest value for orthopedic dentistry. Chewing can be made in high-grade only in case the teeth of the mandibleand maxilla come into contact (occlusion). Occlusion is the basic property of chewing movements. Other functions (speech, swallowing) are performed when dentitions are opened.
The mandibleof the person makes movement in three directions:
– Vertical (upwards and downwards) that corresponds to opening and closing of the mouth;
– Sagittal (forward and backward);
– Transversal (to the right and to the left).
Each movement of the mandibletakes place in simultaneous sliding and rotation of the articular heads.
Vertical movements of the mandible.Vertical movements correspond to opening and closing of the mouth and are made owing to alternate action of the muscles lowering and lifting of themandible.
Lowering of the mandibleis performed by contraction of the digastric (anterior belly), mental-hypoglossal and mylohyoid muscles.
In closing of the mouth lifting of themandibleis performed by contraction of the masticatory, temporal and medial pterygoid muscles.
In opening of the mouth the articular heads slide along the slope of the articular tubercle downwards and forward.
In maximal opening of the mouth the articular heads are established at the first line of the articular tuber. Thus various movements take place in different parts of the joint. In the upper part there is sliding of the disk together with the articular head downwards and forward, and in the lower part the articular head rotates in a deepening (recess) of the lower surface of the disk for which it is a mobile articular fossa.
In opening of the mouth each tooth of the mandiblefalls downwards and, being displaced back, describes a concentric curve with a general centre in the articular head. As the mandiblefalls downwards and is displaced back, curves in space in opening of the mouth, the axis of rotation of the articular head will be displaced.
The way passed by the articular head regarding the slope of the articular tubercle refers to as the articular pathway. The articular pathway represents not a regular curve but the broken line consisting of great number of curves.
In various phases of movement of the mandiblethe centre of rotation will be displaced (by Gizie).
Sagittal movements of themandible.Sagittal movements of themandibleare made by bilateral contraction of the lateral pterygoid muscles.
Movement of the mandibleforward can be divided into two phases. In the first phase the disk together with the head of the mandibleslides along the articular surface of the tubercles. In the 2-nd phase sliding of the head is joined by its swivel movement around the transversal axis proper passing through the head.
The distance which the articular head passes in movement of the mandibleforward is called sagittal articular pathway. The sagittal articular pathway is characterized by the certain angle. It is formed by crossing of the line lying on continuation of the sagittal articular pathway with the occlusalplane. The angle of the sagittal articular pathway, according to Gizie, is on the average equal to 33°.
The pathway made by the lower incisors in pushing of themandibleforward, refers to as sagittal incisor pathway. The angle is formed in crossing the line of sagittal incisor pathway with the occlusalplane which is called the angle of sagittal incisor pathway. According to Gizie it is on the average equal to 40-50°.
In anterior occlusioncontacts in 3 points are possible:
– the 1-st is located on the anterior teeth;
– Two – on the distal tubersof the third molars.
This phenomenon has received the name of Bonwill triangle .
Transversal movements of themandible.Lateral movements of the mandibleresult from unilateral contraction of the lateral pterygoid muscle. In movement to the right the left lateral pterygoid muscle is contracted, in displacement to the left – the right one.
The articular head on one side rotates around the axis going almost vertically through the articular process of the mandible. Simultaneously the head of another side together with a disk slides along the articular surface of the tubercle. In movement of themandibleto the right, the articular head on the left side is displaced downwards and forward, and on the right side it rotates around the vertical axis.
The articular head is displaced downward and forward and a little outside on the side of the contracted muscle. Its way is thus at the angle to the sagittal lines of the articular pathway. This angle was described for the first time by Benet and for this reason it is named by his name (the angle of the lateral articular pathway), on the average it is equal to 17°. On the opposite side the ascending ramus of the mandibleis displaced outside, thus standing at the angle to the initial position.
Transversal movements are characterized by certain changes of occlusalcontacts of the teeth. As the mandible is displaced alternatively to the right and to the left, the teeth describe curves crossed at a blunt angle. The farther the tooth stands from the articular head, the blunter is the angle.
Of significant interest are changes of mutual relations of the masticatory teeth in lateral excursions of the jaw. In lateral movements of the jaw it is accepted to distinguish two sides: working and balancing The teeth are positioned against each other by homonymous tubers on the working side, and on the balancing side – by heteronymic, i.e. the buccal lower tubers are positioned against palatal ones.
In chewing of food the mandiblemakes a cycle of movements. Gizie has presented cyclicity of movements of the mandible in the form of the scheme given below.
1. The initial moment of movement is position of central occlusion
2. The jaw is lowered and pushed forward
3. The jaw is displaced aside (lateral movement) and the teeth join at the working side by homonymous and at the balancing one – by heteronymic tubers
4. The teeth come back in the position of central occlusionand the chewing cycle is repeated
Occlusive surface of natural teeth is a part of a toothsurface from the tubercle apices to the deepest site of central fissure. It is characterised by the anatomic features genetically adapted for function.
Occlusal surface has the following elements: tubercle apices, their bases, clivi, crests, triangular protuberances of tubercle clivi and limiting the so-called occlusaltable marginal fossae, central and additional fissurae.Internal clivi of teeth tubercles are turned to central fissure.
A: 1 – apex of palatal tubercle; 2 – the triangular protuberance of internal tubercle clivus; 3 – central fissure; 4 – marginal fossa; 5 – tubercle crest; 6 – apex of buccal tubercle; 7 – marginal protuberance on periphery of оcclusal surface; 8 – external tubercle clivus; 9 – tubercle basis;
B: 1 – cutting edge; 2 – tooth tubercle; 3 – the medial protuberance; 4, 5 – mesial and distal marginal protuberances; 6 – fossae.
Tooth tubercles are the basic element of occlusal surfaces. Their arrangement defines the tooth form. Every tubercle has the basis, the apex and clivi.
The tubercle apex of each tooth is a little displaced to the middle of a masticatory surface. The apices of all tubercles are connected with the marginal protuberance which limits occlusal surface on periphery. Transverse greatest diameter of a tooth is 2 times more than diameter of occlusal surface. From the apex of tooth tubercle to the middle of its masticatory surface triangular protuberances pass. On these convex protuberances to tubercle crests the opposite оcclusal surfaces slide.
B – external, vestibular; D – distal; M – mesial; Н- oral surface of a tooth; 2, 1 – mesial and distalclivi of buccal tubercle; 4, 3 – mesialand distal clivi of palatal tubercle; 5, 6, 7, 8 – internal tubercle clivi; 9, 10 – marginal fossae. Between the tubercle apices and the tooth centre there are triangular protuberances of tubercle clivi. Internal tubercle clivi 5, 6, 7, 8, limited with the marginal protuberance- «оcclusal table».
Tubercle clivi turned to the central fissure, designate both internal, oral and vestibular located and external ones. In аproximal areas the tooth has mesial and distal marginal fossae. Marginal fossae of two number of the located teeth form a fossa for tubercle of a tooth-antagonist.
Central fissura divides buccal and lingual tooth tubercles. In central and additional fissures the clivi and crests of the main tuberces converge.
Оcclusal (palatal) surface of the anterior incisors and canines with mesial and distal sides has two marginal protuberances which are joined in the inferior third of a tooth with tooth tubercle. Between the middle of the cutting edges and this tubercle the median palatal protuberance is located on either side of which there are septa. Tooth tubercle is the most convex part of a tooth – a place of оcclusal contacts.
Buccal tubercles of inferior and superior palatal masticatory teeth are called basic as they crush the food, define the character of movings of the lower jaw in the limits of occlusal area, redistribute masticatory forces so that the basic chewing loading was on a tooth axis.
Lingual tubercles of inferior and superior buccal masticatory teeth are called not basic, “protective”. In central оcclusion they have slight contact with antagonists or, according to a number of authors, have no such contact. These tubercles carry out the function of food division, create sliding surfaces for antagonists on the clivi, protect the tongue and cheeks from their hit between teeth in chewing.
Dot (not junction) numerous uniform contacts of teeth-antagonists is the most favorable form of occlusion for masticatory function which should be created at modelling of occlusal surfaces. Processing of food of any consistence is thus possible, chewing pressure is distributed on an axis of a teeth, loading on paradontum is minimal, small dot contacts reduce obliteration of masticatory surfaces. Contact of tubercles and fissurae by a principle of «a pestle in a mortar» creates stability of the lower jaw in position of central оcclusion, does not interfere with moving of the lower jaw in limits of occlusal area.
Circles are basic buccal tubercles of the lower teeth and corresponding contacts withteeth of the upper jaw; black points are the basic palatal tubercles of the upper teeth and corresponding contacts with teeth of the lower jaw.
Tubercles of each tooth should be so located that in lateral movements of the lower jaw they passed «in flight» between tubercles of opposite teeth and that there was no оcclusal obstacles in the working and balancing sides.
The factors defining a relief of occlusal surface («occlusion factors »)
The arrangement and expressiveness of basic tubercles and fissurae of lateral teeth as well as relief of palatal surface of superior and vestibular surface of the lower forward teeth, occlusal contacts in positions of lateral and a anterior оcclusion depend on individual factors. They concern:
– Corner of saggital articulate way, movement and Bennett’s corner;
– Expressiveness degree of compensatorycurves;
– Position of оcclusion surfaces in relation to saggitalarticulate way;
– intercondilar distance;
– incisor overlapping.
The less height and convex of a back clivus of articulate tubercle, the slower the lateral teeth go out from the contact at the movements of the lower jaw directed with the teeth. For prevention of paradontum overloadand оcclusal obstacles tooth tubercles should be more flat, and fissurae are superficial. In considerable height and convex of articulate tubercle and the big corner of saggital articulate way the tubercles of lateral teeth should have more abrupt clivi and fossae should be deep. Flat incisor overlappingis corresponding to flat articulate tubercle, flat tubercle of lateral teeth; considerable inciror overlapping and high tubercle of lateral teethare observedin steep articulate tubercle.
The important factor of occlusion is expressiveness of compensatory curves.
Saggital occlisive curve passes from cutting edges of the inferior incisors on the apices of vestibular tubercles of inferior premolars and molars. The more curve is expressed, the more flat the tubercles should be as at promotion of the lower jaw forward there is an insignificant removal of lateral upper and lower teeth from each other. The flat curve should correspond the high tubercles and deep fissurae.
Transverse оcclusive curve (Wilson’s curve) is formed because vestibular tubercles of the lower teeth higher than lingual. This curve passes in transverse surface on tubercles of lower teeth.
As many factors of occlusion are difficult for defining and considering in clinical practice, it is possible to recommend the following variant of functional occlusion: creation of a stable support of lateral teeth in central оcclusion and «canine conducting» with instant disjunction of lateral teeth in eccentric оcclusions.
In the orthopedic purposes from difficult biodynamics of occlusion two main conditions are singled out: articulation and оcclusion. The definition of an articulation given by A.J.Kats is the most spread, namely: these are every possible positions and movings of the lower jaw in relation to the upper one, carried out by means of masticatory muscles. This definition includes not only masticatory movements of the lower jaw, but also its moving during conversation, singing, etc., and also various kinds of closing, that is occlusion.The occlusion is the private kind of articulation meaning the position of the lower jaw at which this or that quantity of teeth is in contact, that is closing. 4 principal types of occlusion are distinguished:
1) central (denture closing at which the biggest number of teeth contacts);
2) anterior;
3) left lateral;
4) right lateral.
The character of denture closing in position of central оcclusion is called a bite. The majority of authors divide all kinds of occlusions on physiological and pathological.
The bites providing full-grown function of chewing, speech and aesthetic optimum concerns to physiological.
Such kinds of denture closing at which functions of chewing, speech or appearance are broken,are called pathological. Anomal occlusions which V.J.Kurljandsky allocates in the separate, third group of bites arepossible to refer to them.
Division of occlusion on physiological and pathological in certain degree is conditional, because the normal occlusion under the known conditions, for example paradontal diseases or loss of separate teeth and their moving, can become pathological.
Physiological occlusion includes: оrthognathic(psalidodontic that is scissor-like), direct (labiodontic that is forseps-like), bioprognathic(when anterior teeth of both jaws together with alveolar crests are inclined forward), opistognathic(when frontal teeth together with alveolar crests of both jaws are directed backward).
Orthognathic occlusion is the most widespread among Europeans (75-80 %). It is characterised by certain signs central оcclusion, one of which concerns all teeth, others – only to anterior or masticatory teeth, the third – to a joint and muscles.
Signs of central оcclusion in orthognathic bite. The superior denture has the semiellipse form, inferior one – parabola form.
Buccal tubers of the superior small and big molars are located outside from the tubers of inferior premolarsand molars. Thanks to it palatal tubers of the upper teeth get to longitudinal sulci of the lower ones, and buccal tubersof the lower teeth – in longitudinal sulci of the upper ones.
Overlapping of anterior inferior and lateral teeth with the superior ones is explained with the fact that superior dental arch is wider than the inferior one. Thanks to it the range of lateral movements of the lower jaw increases.
Each tooth, as a rule, is closed with two antagonists – main and accessory. Each upper tooth is closedwith inferior one and behind standing, every lower – with with the same upper one and standing before. The exception is a wisdom tooth of the upper jaw and the lower central incisor, having one antagonist. This feature of relation of the lower and upper teeth can be explained with the fact that the upper central incisors are wider than the lower ones. For this reason the upper teeth are displaced distally concerning the teeth of the lower denture. The upper wisdom tooth is narrower than the lower one, therefore distal displacement of the upper denture is levelled in the area of a wisdom teeth and their back surfaces lay in one plane.
The average lines which are passing between the central incisors of the upper and lower jaws, lay in one saggitalplane. It provides an aesthetic optimum. Symmetry infringement does a smile ugly.
The upper frontal teeth overlap the lower ones approximately on one third of the height of a crown. The lower frontal teeth contact with tooth tubercle of the upper oneswith theircutting edges (cutting-tubercular contact).
The frontal buccal tuber of the first upper molar is located on the buccal side of same lower molar in its transverse sulcus, between buccal bufs. Posterior buccal tuber of the first upper molar is located between postbuccal tuber of the same lower molar and antebuccaltuber of the second lowe molar. This position of the molar tubers of the upper and lower jaws is often called mesiodistal ratio.
Mandibular head is at the basis of the posterior clivus of articulate tubercle.
The muscles levating the lower jaw are in a condition of uniform contraction.
Starting position of the lower jaw in mouth opening is central оcclusion, and there can be a condition when lips are closed, and the lower jaw droops a little. Thus between dentures there is an interval in 2-4 mm (it is called interocclusal space), that is such position is characteristic for a condition of relative physiological rest. The masticatory muscles thus are in a condition of minimal or, more correctly an optimal tone, that is muscles have rest. The vertical size of the lower third of the face thus is constant for each person and is bigger than that one in central оcclusion or the so-called оcclusal height.
Closing movement of the lower jaw from the rest position to position of maximal intertubercular dental contact incentral оcclusion. RP – rest position; CО- central оcclusion (intertubercular tooth closing).
Interocclusal space is clinically defined as a difference between height of rest and occlusal height at use of the same random points on the face. These points are chosen at random.
Interocclusal space varies on the average in limits from 2 to 4 mm. However in separate persons it can change from 1,5 to 7 mm. Clinical position of rest varies during a life as a result of teeth removal and bite changes.
In random closing movement of the lower jaw from position of rest it moves directly to the position of central оcclusion.
Condition of relative physiological rest is one of articulation positions of the lower jaw at the minimal activity of masticatory muscles and a full relaxation of mimic muscles. The tone of the muscles levating and lowering the lower jaw is equivalent.
In the diagnostic plan it is expedient to consider biomechanics of the lower jaw during food intake and to concretise thus a ratio of dentures and elements of temporo-mandibular joints. In the beginning visual and olfactory analyzers, the memory apparatusact. On the basis of the food analysis the starting mechanism of activity of salivary glands and the muscular device is on, i.e. there is a choice of the optimal program of action. Saliva discharge makes for its necessity to swallow. Thus thanks to contractiveactivity of muscles the lower jaw moves into central оcclusiveposition from a condition of physiological rest then swallowing takes place. Denture closingin swallowing is accompanied by substantial increase of masticatory muscle toneand certain force of jaw compression.
Depressoring of the lower jaw is carried out owing to its weight and as a result of muscle contraction: m. mylohyoideus, т. geniohyoideus, m. digastricus.
Vertical movements of the lower jaw correspond to mouth opening and closing. For mouth opening and food introduction to the mouth is characteristic, that during this moment the chosen optimal variant of action dependingon the visual analysis of food character and the size of a food lumpworks. So, the sandwich, sunflower seeds place in group of incisors, fruit, meat – closer to a canine, nuts – to premolars.
the Schematic image of the muscles taking the basic part in mouth opening.
Thus, in mouth opening the spatial displacement of the whole lower jaw takes place.
Depending on amplitude of opening of the mouth this or that movement prevails. In insignificant opening of the mouth (whisper, silent speech, drink) prevails rotation of a head round a transverse axis in the lower region of a joint; in more considerable opening of the mouth (loud speech, biting the food off) the sliding of the head and disk on a clivus of articulate tubercledownwards and forward joins to rotary movement. In maximal opening of the mouth articulate disks and mandibular heads are established at the apices of articulate tubercles. The further movement of articulate heads is kept with pressure of muscular and ligamentous apparati, and again only rotary or joned movementremains.
Movement of articulate heads in mouth opening can be tracked, having placed fingers in front of the ear tragus or having inserted them in external acoustic duct. The amplitude of mouth opening is strictly individual. On the average it is equal to 4-5cm. Mandubular denture makes a curve in the mouth opening which centre lays in the middle of an articulate head. The certain curve is made also by each tooth.
Saggital movements of the lower jaw. Movement of the lower jaw forward is carried out basically at the expense of bilateral contraction of lateral pterygoid muscles and can be divided into two phases: in the first one- the disk together with a head of the lower jaw slides on an articulate tubercular surface, and then in the second phase jointed movement joinsround the transverse axis passing through the heads. This movement is carried out simultaneously in both joints.
The distance which articulate head passes thus,is called saggital articulate way. This way is characterised by a certain corner which is formed by crossing of the line which is continuation of saggital articulate way with occlusive surface. The latter is a surface passing through cutting edges of the first incisors of the lower jaw and distal buccal tubers of the last molars. The corner of saggital articulate way is individual and fluctuates in limits from 20 to 40 °, but its average size, according to Gyzy, is 33 °.
Such combined character of movement of the lower jaw is available only for the person. The corner size depends on an inclination, degree of development of articulate tuber and overlapping sizes of the lower teeth with the upper frontal ones. In their deep overlapping head rotation will prevail, in small overlapping – sliding. In direct bite movement will be basically sliding. Advancement of the lower jaw forward in оrthognathicbite is possible in the case that incisors of the lower jaw leave overlapping, that is at first there should be a lowering of the lower jaw. This movement is accompanied by sliding of the lower incisors on a palatal surface of upper to direct сlosing, that is to frontal occlusion. The way made thus by the lower incisors is called saggital incisive one. In its crossing with occlusive surface a corner called a corner of saggital incisive way is formed
Оcclusive curves: a – saggital of Shpee; b- transverse of Wilson.
It also is strictly individual, but, according to Gysy, is in the limits of 40-50 °. As in movement mandibulararticulate head slides downwards and forward the back part of the lower jaw falls downwards and forward on the size of incisive slidings. Hence,in the lowering of the lower jaw the distance between the masticatory teeth, equal to size of incisive overlappings should be formed. However iorm it is not formed, and contact remains between masticatory teeth. It is possible thanks to an arrangement of masticatory teeth on saggital curve called occlusivecurve Spee (Shpee). It is called compensatory by majority of people.
The surface which is passing through chewing platforms and cutting edges of teeth, is called окклюзионной. In the region of lateral teeth occlusive surface has the curvature directed by the convexity downward and which is called saggital occlusive curve. Occlusive curve is distinctly marked after eruption of all constant teeth. It begins on posterior contact surface of the first premolar and finishes on distal buccal tuber of a wisdom tooth.
There are essential disagreements of an origin of saggital occlusive curve. Gysi and Schröder (Schroder) connect its development with anteroposterior movements of the lower jaw. According to their opinion, the appearance of curvature surfaces is connected with functional adaptability of dentition The mechanism of this phenomenon was represented in the following way. In advancement of the lower jaw forward its back side falls down and between the last molars of the upper and lowerjaws there should be a lumen. Thanks to the presence of saggital curve this lumen is closed in advancement of the lower jaw forward. For this reason the given curve was called compensatory.
Except saggital curve transverse curveis distinguished. It passes through masticatory surfaces of the molars of the right and left sides in transverse direction. Different level of buccal and palatal tubercle arrangement owing to teeth inclination towards a cheek causes the presence of lateral (transverse) оcclusive curve – Wilson’s curves with various radius of curvature at each symmetric pair of teeth. This curve is absent at the first premolars.
Saggital curve provides contacts of dentitions at least in three points: between incisors, between a separate masticatory teeth from the right and left sides in advancement of the lower jaw forward. This phenomenon has beeoted for the first time by Bonvill and in the literature it is called Bonvill triangle. In the absence of a curve the masticatory teeth do not contact and sphenoid crackis formedbetween them.
Connection between saggital incisive and articulate ways and the character of occlusion was studied by many authors. Bonvill on the basis of his research has deduced the laws which became the basis of construction of anatomic articulators.
The most important laws:
1) Equilateral Bonvill triangle with the side equal to 10 sm;
2) Character of tubers of masticatory teeth is in direct dependence on the size of incisive overlapping;
3) The line of closing of lateral teeth is bent in saggitaldirection;
4) In movements of the lower jaw aside – сlosing with the same bufs, on balancing side – heteronymic.
American mechanical engineer Ganau in 1925-26 has expanded and has deepened these positions, having proved them biologically and having underlined natural, directly proportional connection between elements:
1) bysaggital articulate;
2) by incisive overlapping;
3) by the height of masticatory bufs;
4) by expressiveness of Shpee curve;
5) by occlusive surface. This complex was included into the literature under the name of “articulation Ganau quintuple”.
«Ganau quintiple » is possible to express in the form of the below-mentioned formula:
YSX OS + OK+H
Y – an inclination of saggital articulate way; S – saggital incisive way; Н- height of masticatory bufs; OS – occlusive surface; OK – occlusive curve.
Articulation and occlusion
Definition of terms “articulation”and “occlusion” causes to many disagreements and discussions between dentists for many years. Concept “articulation” come from general anatomy, where it means “joint, conjugation”. Full and correct definition of an articulation gives A.J.Katts (1931). He said that “articulation” it is different positions and mandible movements as concept in relation to top which are carried out by means of masseters and under CNS control.
Articulation – is a mutual relation of dentitions during mandible movements.
Occlusion – it is closing of dentitions in whole or separate groups of teeth throughout larger or smaller to an interval of time. Thus, the occlusion can be surveyed as the articulation special case. The forward occlusion is closing of dentitions during time moving out a mandible forward. The lateral occlusion is closing of dentitions during mandible shift aside. Distinguish three kinds of an occlusion: forward, lateral and central. Forward occlusion – it is closing of dentitions during time of moving out forward a mandible, lateral occlusion – closing of dentitions during mandible shift aside, definition of the central occlusion as initial and final moment of an articulation.
There is also a definition of the central occlusion as initial and final moment articulations (G.Müller). It is offered to define the central occlusion in case of an orthognathic occlusion as closing of teeth which are characterized at least by such four signs:
1. Each top or bottom tooth is closed with two antagonists: top – with the bottom teeth (with the same and that behind), bottom – with an upper teeth (with the same and that ahead). Exception are an upper teeth of wisdom and the bottom central incisors which have only on one antagonist. 2. Middle lines between the top and bottom central teeth is continuation each other and located in one sagittal plane. 3. The top face-to-face teeth blocks bottom almost for 1/3 lengths of a crown of tooth (1,5-3 mm). 4. The top first molar, being closed with two bottom molar, blocks approximately 2/3 first molar and 1/3 the second. The bucco-medial hill of the top first molar gets in locking cleft between buccal hills of the bottom first molar.
SAGITTAL, VERTICAL AND TRANSVERSAL MOVEMENTS OF THE MANDIBLE AND THE MUSCLE WHICH CARRY OUT THEM
Vertical movements answer not only for opening, but to closing of a mouth and are carried out thanks to a serial relaxation and reduction of muscles which lower and lift a mandible. Mandible lowering is carried out during active reduction of mylohyoid muscle, geniohyoid muscle, under condition of bracing of a sublingual bone by muscles which are more low from it. During mouth opening simultaneously with rotation of a mandible round an axis which passes through mandible heads in a cross-section direction, the last slip on a clivus of an articulate hill downwards and forward. During the maximum opening of a mouth of a head of a mandible settle down on a first line of an articulate hillock, in that case in different departments of a joint. If to part a way which there has taken place a mandible head rather to a clivus of an articulate hill (articulate a way) on separate pieces each piece will be answered with the curve. Thus, all way passed by any point, located, for example, on mental pleading, will describe not a correct curve, and a broken line which will consist of many curves.
Sagittal movements of a mandible. Mandible movements forward are carried out by bilateral reduction of the lateral pterygoid muscles fixed on the one hand in fossas of pterygoid processes, from another – on a forward surface of a head of a mandible an articulate disk. Mandible movement forward can be parted on two phases. In the first phase the disk together with a mandible head slips on a surface of an articulate hill. In the second phase its hinged movement joins head sliding round own cross-section axis. The distance which there takes place a head of a mandible during mandible movement forward, has the name of a sagittal articulate way. It is characterized by the allocated angle – an angle of a sagittal articulate way.
Lateral movements of a mandible. Lateral motions of a mandible result from reduction of a pterygoid muscle on the one hand. During jaw movement the right lateral pterygoid muscle to the left is reduced. In that case the head on the one hand rotates about the axis which goes almost upright downwards through a mandible branch. Simultaneously the head on the other hand together with a disk slips on a surface of an articulate hill. If the mandible moves, for example, to the right on the left side its head moves downwards and forward and from the right rotates round a vertical axis. Angle of a lateral articulate way. The mandible head on the party where the muscle was reduced, moves downwards, forward and (slightly) to the middle. Thus it overcomes a way at an angle to a sagittal line of the joint ways. Lateral movements are characterized by certain changes and occlusal contacts of teeth. As the mandible is constantly displaced that to the right to the left, teeth describes at this time curves which are crossed at an obtuse angle. The further from a mandible head there is a tooth, the the angle is more. The angle which is formed in a place of crossing of incisors, is the most obtusive. This angle is called as an angle of the lateral incisor ways, or a Gothic angle. It defines amplitude of lateral motions of incisors and equals 100-110 °. The great interest is caused by changes of mutual relation of chewing teeth during jaw lateral motions. During jaw lateral motions two parties distinguish: working and balancing. On the working party teeth faces the hills with the same name, and on balancing – heteronymic, that is buccal bottom hills face the top palatal.
CLINICAL METHODS OF INSPECTION
The basic task of this stage of diagnostic research is such: to collect separate facts in a certain sequence, to unite them in groups logically dependent between itself and, leaning against knowledge of individual and age-old features of structure of organs (fabrics) of the tooth – jaw system, functional anatomy and biomechanics of masticatory vehicle, to pass to comparison with the symptoms of the known stomatological illnesses. Determination of degree of authenticity and exactness of found out symptoms is possible after the sufficient capture by the technique of clinical and special (laboratory) methods of inspection.
The exposure of pathological changes in organs and fabrics of maxillufacial area is conducted in a certain sequence with the use of general clinic receptions: to the review, percussion, auscultation, palpation.
Review and inspection of person
Because of the ethics considering, it follows to conduct the external review of person unnoticed for a patient during a talk. In the process of inspection anatomic descriptions, morphological and functional features of person, are studied. Criteria which make an aesthetically beautiful optimum concerne thus: type of person, symmetry of right and left halves of person, vertical size of lower department of person, expressed chin and nosolabial skinnings furrows, correlation ofoverhead and lower lips, position of corners of mouth, size of baring of crowns of the teeth during broadcasting and smile, degree of opening of mouth.
The face of the grown man has individual lines, on forming of which the developed of cerebral department of skull, bone and muscular systems of masticatoryvehicle influences. It is accepted to select four types of person.
Cerebral – is characterized by considerable development of bones of neurocranium. The high and wide frontal department of persootedly prevails above other departments, as a result a person reminds the form of pyramid with the basis aimed upward.
Respirator – is characterized to predominances of development of middle department of person. Strongly the developed genyantrums, temples arcs relief come forward ahead, and that is why a person has a diamond-shaped form.
Dihestiv – is characterized by considerable development of lower department of person. Overhead and lower jaws are superfluously large, a masticatory musculature is strongly expressed. At presence of narrow frontal part a person reminds the form of trapezoid.
Muscle – is characterized by the approximately equal sizes of overhead and lower departments of person, border of hairs in the area of forehead usually line which gives to the face of square form.
It is needed to mean, that the face of man is disproportionate, however guilty the asymmetry of his halves, predefined by the different degree of development of the symmetric located anatomic educations, is not to be considered as deviation from a physiology norm. Asymmetry of person is obviously expressed is observed at the inflammatory and tumular processes of maxillufacial area, violation of innervation of masticatory and mimic musculature and as a result of traumatic damages.
In the clinic of orthopaedic stomatology dividing of vertical size of person is accepted by three parts: overhead, middle and lower third. The overhead third of person is located between the border of growth of hairs on a forehead and line which connects eyebrows. The middle third of person is distance between a line, which connects eyebrows, and basis of skinning membrane of nose. Basis of skinning part of membrane of nose and lower edge of chin serve as the scopes of lower third of person.
Hem of height of person on three parts it follows to acknowledge conditional, as positions of scopes, which measuring individual enough and during life changes is carried out in accordance with. Yes, the overhead third of person with age can be multiplied due to moving of border of growth of hairs on a forehead. The height of lower third of person also is not permanent and depends on the type of closing and stored of teeth. Least changeable middle third of person.
Without regard to that between the sizes of the indicated parts of person it is heavy to see an appropriate proportion, in most persons they have relative accordance which provides an aesthetically beautiful optimum.
The large practical value is had by the anatomic features of lower departments of person. The expressed of chin-lip furrow allows to assume the presence of supraocclusion, dystal displacement of lower jaw with diminishing of vertical size of lower third of person as a result of loss of lateral teeth or their pathological rubbing off . About the same the formation of jam testifies in the corners of mouth. Falling back of lips testifies to absence of frontal group of teeth, and in combination with the expressed nosolabial furrows – about the complete loss of teeth or considerable degree them rubbing.
Such rejections are set in the process of review obligate to conduct measuring of linear sizes of height of lower department of person, that it is important enough for constructing of removable prosthetic appliances. It is accepted to distinguish two vertical sizes of lower third of person: height of relative physiology rest and occlusal height. The height of relative rest is characterized by that muscles which lift and drop a lower jaw as well as mimic, are in the weak state, and between teeth there is a road clearance. At the dense closing of dental rows muscles which levitate a lower jaw become taut in position of central occlusion (occlusal height).At the physiology types of bite the difference of vertical size of lower department of person in relative physiology rest and centrally-occlusal correlation of jaws makes 2-6 mm.
The attentive review of person allows to set carried before or concomitant general somatic illnesses: presence of scars in the area of overhead lip, which touchthe red framing, testifies to the operation concerning the nonunion of lip. Dryness of skinnings covers and presence of original grasping folds of skin in the area ofoverhead and lower lip with diminishing of size of mouth crack allows to assume a presence at the patient of system scleriasis, scars is investigation of thermal and chemical burns – condition necessity of decision of structural features of dentures and medical vehicles and clear determination of all medical manipulations, beginning from the method of preparing of teeth, features of receipt of imprints to the method of introduction and fixing of prosthetic appliances in the cavity of mouth.
A review and inspection of teeth must be conducted in the set procedure, beginning from the wisdom tooth of one side to the of the same name tooth of the second side. Thus does not have the of principle value, from what jaw to begin a review (overhead or lower), and direction of review (business or on the left) ofexamination teeth is conducted by the surveying set of tools: stomatological mirror, pincers, probe. Application of mirror allows to examine every tooth from every quarter, by pincers determine mobile of teeth, a probe serves for establishment of safety of surface of crown of the tooth, sensitiveness of areas of tooth, depth of tooth – gum groove or perіodontal pocket. The estimation of teeth consists of position-finding tooth in a dental arc, form, color, state of hard fabrics of crown part (presence of stoppings and artificial crowns), firmness of tooth, correlation of retroalveolar and intraalveolar his part. Deviation of tooth from normal position in a dental arc is one of symptoms, what allow in the complex objective and anamnestic data analysis to set, a tooth deviated from the initial position or it is his individual (anomalous) position. Distinguish displacement of teeth in an intact dental row, at the defects of dental rows and as a result of wrong his eruption. Directions of displacement of teeth in the formed tooth – jaw system are varied enough: in vestibular or oral direction, in medial or distal in vertical direction (below or higher occlusal plane of dental row), turn of tooth about vertical axis (rotary displacement). The change of position of tooth set during a review in any direction is the symptom of different illnesses of the tooth – jaw system and needs lead through of additional (special) researches with the purpose of establishment of mechanism of his displacement.
Studying character, topography and degree of defeat of hard fabrics of tooth, it is necessary to lean against the knowledges of anatomic form of every explored tooth, comparing with got during the inspection by information. More frequent in all the form of tooth is changed as a result of cariosity, when demineralizing and softening influence of hard fabrics is with subsequent formation of defect. Localization and frequency of defeat of different teeth is different. The study of localizationof defeat of different groups of teeth (Blac) allowed to find out certain conformities to the law.
Reason of violation of form of teeth can be the uncarious defeats: hypogenesis of enamel, hyperplasia of enamel, displasia.
At a system hypogenesis chisels take barrel likeness shape with the half of moon undercut on a cutting edge (teeth of Furn’e, Hetchynson), and molars – characteristic cone-shaped form (teeth of Pfluger). Hyperplasia of enamel shows up to surplus formations of fabrics of tooth in the area of neck, and also on contact surfaces. Sharply the form of tooth changes at displasia of Staton – Kapdepon. Through the inferior structure of hard fabrics of teeth soon after their eruption an enamel breaks away and there is elimination of teeth.
Frequent reason of change of form of teeth is pathological rubbing, that is characterized to the considerable diminishing of hard fabrics, and wedge – shaped ( V – shaped) defects, which appear in the near neck area of vestibular surface of premolars, canines, chisels. If in the process of review found out the teeth of the changed color, they are subject to the detailed study. The color of natural teeth has individual features which are investigation of stratification of colouring of enamel on colouring of dentine. A dentine has yellow of different tints. Color of enamel is white with yellow, blue, rose, grey by tints or with their combination. That is why the threshold surface of foreteeth has three coloured nuances: the cutting edge of foreteeth, which does not have dentine – layer, is often transparent; middle part which is covered by more thick layer of enamel and does not enable to be translucent to the dentine is less transparent; iear neck part the layer of enamel is thinner and a dentine through him examines with x-rays stronger, that is why this area of crown of the tooth has the expressed rather yellow tint.
At young persons the color of teeth on the whole is lighter, at adults, especially old people, he has more expressed rather yellow or greyish tint. In special cases, in particular in those, who burns, different pigmentations and atypical discolorations teeth appear. The color of tooth can change and depending on the degree of cariosity: disappearance of natural brilliance of enamel, chalky spot, colouring of carious spot from grey to the umber tones. As a result of application of amalgam for treatment of caries the color of tooth can change oavy blue, and from the use of plastic materials – on an umber. The enamel of teeth a vascular-nervous bunch (teeth pulps) is remote in which loses brilliance and acquires a greyish-yellow tint. At a fluorosis the mat appear on teeth, light – or umbers areas of pigmentation. In future there is formation of erosions on these areas of enamel.
For the inspection of teeth widely use the methods of percussion, sounding and palpation.
Percussion is conducted in the opened mouth of patient by the easy pattering by the handle of probe on different areas occlusal (axial percussion) and threshold (angular percussion) surfaces of tooth.
Percussion of healthy tooth is not sickly and is accompanied by a clear sound loud. In case of occurring of changes in mash and perіodont, force and tint of sound change to resorbtion of bone fabric and fibres of perіodont. By this method determine the state of peryapical fabrics after expressed of the pains feelings, which arise up in reply to the easy shots on a tooth, directed to apex or under a corner to his crown part. In the case of origin of pain from the shots of small force it is not needed farther to multiply effort. After sounds which arise up from pattering, it is possible to define the state of endodontium also. Percussion of tooth with the lost mash, pulp with the sealed channel gives the muffled sound, unsealed – tympanic, that reminds a sound from a blow on a drum.
With the purpose of establishment of differences in the pains feelings and voice vibrations conduct comparative percussion, that percussion of the same names teeth on the right and left side of jaw. At presence of the extended perіodontal crack at axial percussion a blunted sound is heard. Circumstance that axial percussionof healthy tooth gives more hard and loud sound, than angular, testifies to the role of fibres of perіodont in the transmission of vibrations on bone fabric, as at angularpercussion the areas of fibres, which work here on tention, are attracted. A blunted sound arises up at violation of circulation of blood in perіodont. Fillings fabrics out as though take in sounds. At the chronic pathological changes in a apical area, as a rule, dulling of sound appears at angular percussion. Dulling of sound and pain from appear in the case of peryapical and margіnal inflammation, death of dense bone fabric of walls of teethridges.
Soundings apply for determination the depths of carious cavity, degree of softening influence of hard fabrics, for the study of the state of parodont after the second index – state of perіodontal crack at presence of under gum stone.
Palpation is applied for determination of mobile of teeth. This manipulation can be carried out by pincers, probe. The presence of mobile of teeth is the sensible indicator of the state of parodont, symptom of row of illnesses (parodontitis, perіodontyt, sharp and chronic trauma). Distinguish physiology and pathological mobile of teeth. First is natural and unnoticeable. its presence is confirmed to eliminations of contact points and formations of blivets. The pathological mobile is characterized to displacements of tooth from small efforts.
De bene esse distinguish four degree of pathological mobile of teeth: And degree is a tooth moves in vestibal -oral direction; II degree is a tooth moves in vestibal-oral and medial-dystal directions; III degree – to the first two is added vertical mobile of tooth; The IV degree is rotary motions of tooth.
The results of review of teeth bring in a dental formula, following the generally accepted denotations.
The estimation of the state of dental rows of overhead and lower jaws consists in determination of form of dental arcs, amount of present teeth, slowness and topography of defects (substituted for teeth by prosthetic appliances or not), position of every tooth in relation to an occlusal plane, and also in setting of type of bite.
The estimation of the state of dental rows of overhead and lower jaws consists in determination of form of dental arcs, amount of present teeth, slowness and topography of defects (substituted for teeth by prosthetic appliances or not), position of every tooth in relation to an occlusal plane, and also in setting of type of bite.
At a direct bite overhead and lower dental rows have the form of semiellipse. For physiology progenia and physiology prognatia on a background the normal semiellipse of structure of dental row of supramaxilla the frontal area of arc has the forerake accordingly and back.
In the correctly formed tooth – jaw system dental rows make unique whole both in the morphological and in functional relations. Unity of dental row is provided by the between teeth contacts, alveolar sprout, parodont and is unique from the basic terms of valuable function of teeth. The extraction of teeth and appearance of defects in a dental arc result in violation of its continuity, and a dental row here disintegrates on the groups of teeth, which keep antagonists, continuing to execute the function (functional group), other, losing antagonists, appear by excluded from the act of mastication (non-working group).
Setting absence of tooth (teeth), it is necessary to find out reason of loss. Violation of continuity of dental row can be predefined by absence of rudiments of thesecond teeth (primary, an adentia is innate), by the presence of defects in the area of teeth which were not cut through (uneruption teeth). Teeth can be remote after eruption for diverse reasons: caries and his complication, parodontitis (parodontosis), trauma, operative interferences on jaws and other On occasion there are the anomalies of amount (supernumerary teeth) or position (excalation of jaws) of teeth. Similarly there can be the set presence in the formed dental row of teeth of temporal bite.
The large value in diagnostics of the state of dental rows is had by information about a slowness and topography of defect, and also about the presence of neighbouring natural teeth. After a slowness distinguish: small defects are absence not more than 3 teeth; middle from 4 to 6 teeth; large defects, when more than 6 teeth are absent. After the presence of teeth neighbouring with a defect: limited by teeth both-side (included) or from one side (eventual). After the location: included in front, lateral or front – lateral areas of dental row. Variants of absent teeth there can be a generous amount.
In order to systematize the most widespread defects of dental rows, estimate the degree of related to them morphological and functional violations, it is offered a lot of classifications. But classification of Cannadi became most acknowledged, topograhpo – anatomic principle is fixed in basis of which. Development of such classification was predefined to aspiring to the fast and exact diagnostics of violations of dental rows with the purpose of determination of testimonies to the choice of constructions of prosthetic appliances at the different types of defects. An author distributed the defects of dental rows on four basic classes.
The class I. Two – sides, toothless areas the jaws located behind from present natural teeth.
Class II. One-sided toothless area of jaw, located behind from present teeth.
Class III. Toothless space of lateral areas of jaw, limited by present teeth at the front and behind.
Class IV. Toothless space located at the front from present teeth, which crosses the middle line of jaw.
With the purpose of clinical evaluation of correlation of teeth in relation to an occlusal plane: at the parted lips by index fingers take the corners of mouth sick so that from of the red framing of overhead lip central chisels came forward no more than on 0,5 sm, fix the look (the eyes of doctor which stands before a patient are at the level of the parted lips of patient) on verge of central chisels. Thus all dental row of maxilla gets in eyeshot. Imaginary conduct a plane, parallel camper horizontal lines (line which de bene esse connects lobe of the ear of ear with the lower edge of wing of nose), estimate present curvature on an occlusal surface and accordance to his norm or determine displacement downward or upwards in relation to this surface in the group of masticatory teeth. This method is used on condition of absence of rubbing of foreteeth.
It is needed to consider the violation of smoothness crooked, caused by displacement of tooth or row of teeth upwards or downward in relation to neighbouring teeth, a diagnostic symptom. It is the phenomenon which is named the phenomenon Popova – Godona, more frequent in all meets as a result of loss of antagonists. Curvature of occlusal surface can come and at intact dental rows, when part of antagonist teeth is added rubbing (a form is noncommunicative) or the closing surface of teeth is stopped by plastic materials. In these terms simultaneously with elimination of hard fabrics or stopping material there is moving of antagonists teeth. The similar symptom of deformation of dental rows can be set at treatment of partial edentia by removable prosthetic appliances from a plastic or in those cases, when occlusal surface metallic to framework of bridge- likeness prosthetic appliance metal-lined by a plastic. For the exposure to deformation of dental rows conduct comparison of levels of location of neighbouring teeth, estimation of all occlusal plane during the review of dental layer from the side of frontal teeth.
Not coincidence of line of center – vertical between the central chisels of overhead and lower jaws – can be the symptom of different illnesses: defeat of right or left temple – lower jaw joint, break of jaws, pathological alteration in dental rows through the partial loss of teeth, presence of masticatory teeth only on one side.Location of cuttings edges of chisels, and sometimes and dog-teeth of supramaxilla below red framing of lips, considerable their baring during a talk testifies to their moving apeak or vestibular as a result of pathological processes which take place in a paradontium. Displacement in vestibular direction, as a rule, is accompanied to formations of diastem and trem, and teeth as though move aside an overhead lip upwards. Such displacement can result in formation of the opened bite or stipulate moving of lower chisels upwards.
The large diagnostic value has determination of stored of occlusal surface and in the group of masticatory teeth. At orhognatical and biprognatical types of bite and physiology progenia is observed smooth curvature of line of dental row, beginning from first premolar (sagital “curve of E. Shpee“, 1890). On a supramaxilla the line conducted on vestibular or oral knolls and intertubercular furrow forms the segment of circle, reverse downward. Accordingly the same curvature appears in the group of masticatory teeth of lower jaw. The level of these curves is different through inclination of crowns of the teeth in relation to the horizontal plane of location of vestibular and oral knolls, that predetermines the presence of transversal of curves (“curves E. Shpee“, 1918). A sagital curve at a direct bite is absent. This it should be remembered and to interpret not as pathology.
At the defects of dental rows of displacement in vertical direction it is possible to set at serried dental rows, when teeth which lost antagonists are below occlusal surface of antagonist of dental row (or below occlusal line of closing of dental rows). In cases of elimination of teeth-antagonists and absence of elimination or considerably less elimination of teeth, deprived antagonists, crossing by these teeth of occlusal line is not proof of displacement of tooth (teeth), as deformation of occlusal surface is diagnosed due to pathological rubbing.
Displacement of teeth serves as the symptom of deformation of dental rows in medio – distal direction at the partial defects of dental rows, which is named convergence.
Such deformations are characterized by the complex of symptoms: by the change of axis of inclination of crown part of tooth, diminishing distances between teeth, which limit a defect, by appearance of trem between teeth, which abut upon a defect (more frequent between teeth, located medial from a defect), violation of occlusal contacts of teeth, which also abut upon a defect. Sometimes defects in dental rows predetermine rotary displacement of teeth, that moving them about long axis from it is enough to variation violations of occlusal contacts. Estimation of articulating and occlusal correlations of dental rows consists of information about character of motions of lower jaw.
Implementation of basic functions of the teeth – jaw system is related to different character of motions of lower jaw. In default of contact between dental rows motions of lower jaw are sent by brief muscles and articulating surfaces of joints. When dental rows are in the contact, and a jaw moves, character of its displacement mainly concernes by correlation of surfaces of masticatory teeth.
Motions of lower jaw are provided by retractive activity of different groups of masseters on the basis of difficult compounded pavlovian and unconditioned reflexes. As a result of work of muscles a lower jaw moves ahead, back, goes down, rises, is displaced sideways and is gone back into previous position.
Studying displacement of lower jaw as a result of opening and closing of mouth, it is needed expressly to determine linearness of displacement is a line between the central chisels of supramaxilla does not deviate from the same line on a lower jaw. Deviation from linear displacement on the stages of the slow opening and closing of mouth testifies to the pathological processes in a joint (disfunctions, arthritis, chronic dislocation, tention connection of joint) or in the muscular system. Partial loss of teeth (especially masticatory), pathological rubbing predetermines violation of occlusal correlations. Inspecting dental rows in relation to occlusia, it is possible to set that the chisel ceiling is megascopic, and in parts of teeth not two, but one antagonist (the canine of lower jaw contacts only with the canine of supramaxilla). In determination of displacement a diagnostic value is had also by diminishing of the chisel ceiling and establishment in the correct (without the occlusal contacts) contrasting of canines lower jaw and other teeth in relation to the antagonists of supramaxilla in position of lower jaw in physiology rest, and at the slow closing of dental rows there is at first closing of group of frontal teeth (contact on the fasings of closing) with subsequent displacement of lower jaw back and multiplying the chisel ceiling.
It is especially important to estimate evenness and simultaneity of closing of dental rows at the central occlusal contact and presence of numerous contacts during occlusal motions of lower jaw. The exposures on the separate teeth of areas, which at occlusia enter the first into the contact, conduct by sight at the slow closing ofdental rows and stage-by-stage displacement of lower jaw from position of central occlusia in lateral or front occlusia.
Information about the areas of concentration of pressure it is possible to get by occlusiogramme. In the case of establishment of unevenness of contacts together with other symptoms it is possible to find out the source of origin of illness or one of factors: parodontitis, perіodontitis, illness of temple – lower jaw joint. The concentration of occlusal contacts (concentration of masticatory pressure) can be created due to the wrong imposed stoppings, off-grade made crowns, bridge – likeness prosthetic appliances. In addition, she arises up at uneven rubbing of natural teeth and rubbing of false plastic teeth in dentures.
INTERVIEWS WITH PATIENTS
(finding out of complaints, collection of anamnesis)
The first stage of diagnostic research is interviews with a patient, during which reasons of his appeal turn out in a clinic (complaints, subjective feelings), firstsigns of illness (anamnesis of illness), state of health and condition of life (anamnesis of life).
At the beginning of conversation it is necessary attentively to hear out the complaints of patient, his explanation of reasons and character of development of the unusual feelings (subjective symptoms). Subjective information is found out from the story of patient help to define the circle of questions which are based on the first suppositions about character of illness. Timely clarification of separate moments due to the concretely put questions and answer on them allows in future to ground authenticity of complaints and feelings of patient, and also confirm or deny arising hypotheses up.
In the process of dialog symptoms which characterize deviation from a physiology norm and its variants appear with a patient. Summing up and logically comprehending found out the phenomena, defining leading symptoms, it is necessary to confront them with symptoms of the known illnesses.
However especially the classic displays of illnesses meet rarely, more frequent there are the different rejections and combinations of symptoms. The individual reaction of organism acts important part in the change of classic charts of symptoms of illnesses. Exactly she predetermines the necessity of receipt of exhaustive information about the origin and development of illness. It is needed to set: when, as well as under act of what reasons, in opinion of patient, illness began, what motion she had in the moment of appeal in a clinic, whether some treatment was used, which was his efficiency. In detail find out the first signs and displays of illness.
During conversation it is important to set the contact with a patient, to make attempt understand him as personality and to conquer the trust. That is why it follows to pay the special attention to the specific of exposition by the patient of complaints. It will help to make the picture of features of his psyche.
Clinical experience testifies that individual reaction on perceptible subjective symptoms and interpretations of visible sick clinical displays of illness predefined, above all things, by natural properties of psyche, that by temperament. Temperament belongs to the borning internalss of personality of man and concernes by the processes of nervous excitement and braking (by their force, even tempers and mobile). Different combinations of these properties allow to select four basic types ofhigher nervous activity: sanguine, phlegmatic, choleric and melancholy.
A sanguine type is characterized by the strong balanced and mobile nervous processes of excitation and braking. Sanguine type is easily included in the contact, in intercourse; as a rule, optimists. These people adequately perceive said, insistingly and expressly execute all advices and settings of doctor.
For a phlegmatic type the characteristic strong are balanced, but inert nervous processes. To the phlegmatic persons peculiar proof mood, quiet motions and the reaction is slow on the different influencing. They are balanced enough people, but heavily enter into the contact. With them it is necessary in detail and convincingly to converse.
A choleric type is characterized by strong and unstable nervous processes with predominance of excitation. Temperamental persons have the strong nervous system, but impatient, sometimes unrestrained and feverish. They are littlepin, difficult in intercourse.
In a talk with them it is necessary to be restraint, to talk, weighing every word. It is important enough for such man foremost patiently to hear out her, blow about its negativism and try to satisfy of its possibilities.
A melancholy type has weak nervous processes, strong dormancy which arises up under act of strong irritants. Melancholic persons are people with a weak and impressionable psyche. They usually need permanent support, is easily added to suggestion.
Application of such receptions of socializing with a patient and influence on him, without regard to the generalized character, in a great deal determines tactic of medical actions in the process of diagnostic research, final success and prognosis of orthopaedic treatment.
On the origin and character subjectively of perceptible social and natural terms, state of health and vital circumstances, influence by the patient of symptoms.These factors can unfavorable to influence both on an organism on the whole and on the tooth- jaw system in particular. That is why the special value is acquired by information about the presence of general symptoms, inherited and carried illnesses, ecological and productions to harmfulness, usual intoxications and harmful habits. The story of patient and his answers to these questions considerably correct the picture of reasons and terms of development of concrete illness, and also dictate the choice of tactic of orthopaedic treatment.
Thus, on the basis of the set subjective and anamnestic information, logically comprehending found out the phenomena, it is necessary to draw previous conclusion about the presence of that or other form of illness, to come to certain suppositions about its character. Arising up as a result of interviews with the patient of supposition (hypotheses) is instrumental in the purposeful leadthrough of subsequent researches and receipt of exhaustive information about illness.
EXAMINATION OF THE PATIENT IN CLINIC OF ORTHOPEDIC DENTISTRY
The increased course of preclinical training in orthopedic dentistry is aimed not only at studying anatomy and physiology of the organs of the dentomaxillary systems, but also at deeper mastering of the practical skills, and thus at general improvement of training quality of dental students.
Orthopedic treatment of patients is given for final restoration of the maxillodental system, reconstructions of the lost form of some organs of this system, their functional interrelations.
The maxillodental system is organs and tissues interconnected functionally by anatomy, performing various but co-ordinated functions. It contains the hard tissues – bones of the facial skeleton, including the maxilla and mandible, masticatory and mimic muscles, salivary glands, temporomandibular joint – a paired organ – mobile connection of the mandible with the temporal bone of the skull.
In the correctly formed maxillodental system the structure of each organ is precisely coordinated with its function. The compensatory process that is compensation of the impaired function due to activity of the intact organs begins to develop in the damaged maxillodental system, for example, influence of the environmental factors on an organism: physical, chemical, biological, social, with genetic defect or under the effect of local factors. But the compensatory process has a limit which is followed by rather steady deviation from the norm, having biologically negative meaning for an organism, resulting in development of a disease.
Each disease is characterized by certain signs or a group of symptoms. There are subjective and objective symptoms.
Subjective symptoms are symptoms revealed while questioning the patient, the unusual sensations which the patient began to experience. For example, difficulty in chewing food, pain, itching in the gums, dryness in the mouth, retention of food between the teeth, etc.
Objective symptoms are found by the dentist during examination: inspection, palpation, instrumental and apparatus investigation.
Sometimes it is necessary to apply functional methods of investigation to find out the function of the maxillodental apparatus: chewing tests, graphic records of movements of the mandible, investigations of the muscle biocurrents, etc.
A disease can be manifested by one or several objective symptoms, one of which is characteristic only of the given kind of the disease, and others may be observed in other diseases. Examination of the patient is also aimed at making clear the symptoms, etiology and pathogenesis, course of the disease, his physical and mental condition, function of themaxillodental apparatus. Careful and thorough clinical examination of the patient will promote correct diagnosis, purposeful orthopedic treatment.
While examining the patient, the dentist should know precisely significance of physiological norms, possible variants of the structure and functioning of separate organs of the maxillodental system, topography and functional interrelations. Thus he should not only detect the signs, but also be able to interpret them logically, determine the leading symptoms, basing on the examination of the patient. So the dentist should know well all sections of dentistry, a clinical picture of every nosologic form of the maxillodental system.
Examination of the patient is made consistently under a certain plan and includes: the anamnesis (questioning of the patient), external survey, survey and examination of organs of the oral cavity; examination of the temporomandibular joint; examination of the muscles of the head and neck, laboratory and instrumental methods of investigation.
SUBJECTIVE METHODS OF INVESTIGATION
Taking the anamnesis is the first investigation phase of the patient. The anamnesis consists of the following sections: 1) complaints and subjective condition of the patient; 2) anamnesis of this disease; 3) anamnesis of life of the patient.
During the first visit of the patient the dentist listens attentively to the story of the patient about unusual sensations (complaints) which he began to experience. It is important to find out the earliest manifestations of the disease, character and peculiarities of its course, to know the cause of unusual sensations in patient’s opinion. In one case the anamnesis may be very brief and there is no necessity to go into detailed history of the patient’s life, in other cases, for example, when the patient has a feeling of burning in the mucous membrane of the oral cavity under the denture , the anamnesis and all investigations will be detailed with the use of apparatus and laboratory methods with participation of doctors of other specialities.
It is necessary to listen to the patient attentively and patiently, at the same time concentrating his attention to the main, from his point of view, sensations, correctly specifying some moments by purposefully asked questions. All this can determine questions which are required for statement of the diagnosis, special or additional methods of investigation.
While listening to the complaints of the patient it is necessary to pay attention to response of the patient in statement of complaints. It will help to get idea about the type of his nervous activity that is of great importance in choice of construction of a denture and the subsequent adaptation to wearing it, to faster establishment of mutual contact between the dentist and patients.
During inspection it is important to obtain data about the onset of the disease, the cause of its development, its course before referring to the dentist, what treatment was applied, if it was, it is necessary to find out a kind and scope of the treatment.
In some diseases it is difficult to establish the cause of their development. So, for example, pain, burning in the mucous membrane of the oral cavity under the denture can be caused by a badly made denture, a mechanical trauma or allergic reaction to the basic material. The same character of pain are observed in glossalgia, impairment of heat exchange in the tissues of the orthopedic bed, diseases of the gastrointestinal tract. Hence, pain may be caused by various causes, the mechanism of its development is also different.
Sometimes during questioning it is possible to establish that deterioration of a condition of the maxillodental system occurred during some general disease or after it. Then there is a question, whether the revealed disease is independent nosologic form or is one of symptoms of other diseases (stomach ulcer, gastritis, diabetes, etc.). Therefore it is important to assess the general condition of the patient.
The anamnesis of life. The anamnesis of life is a“the medical biography” of the patient. It is of great significant for understanding the causes, conditions of development of the present disease. For example, data about feeding (formula feeding, the use of the soft grated food during formation of milk and replaceable bite) can presumably specify the cause of abnormal development of the maxillodental system.
The birthplace, peculiarities of the environment (lack or excess of fluorine in water) may be the cause of noncarious affection of the teeth in some people.
Harmful working conditions, such as work connected with manufacture of acids, alkalis, coal-mining industry can promote development of pathological abrasion of the teeth.
It is important to find out the sustained illnesses and presence of general somatic diseases at the moment of inspection as they also can promote development of pathological changes in the maxillodental system. The knowledge of their course peculiarities will also help the dentist to choose correct tactics in orthopedic treatment. So, in diseases of the cardiovascular system (myocardial infarction, stenocardia, insult) such injuring factor to this system as preparation of the teeth should be eliminated and it is better to recommend prosthesis by removable dentures. In presence of bronchial asthma, it is impossible to apply the materials having smell for taking inpressions (repin, thyodent, dentafol). They also should not be made relocation of the denture directly in the oral cavity. Otherwise it may cause an attack of asthma. Thus, on the basis of the anamnesis and subjective data of the patient, the dentist makes a presumable conclusion about the character and form of the disease. It is a working diagnostic hypothesis, which will promote the further purposeful investigation to specify the assumptions.
OBJECTIVE METHODS OF INVESTIGATION
Detailed inspection of all organs of the maxillodental system is made for specification of the assumption of the disease and for better understanding of the disease. Data of the objective inspection reject or increase reliability of the assumptions of the disease. The objective inspection includes: external survey, survey and examination of organs of the oral cavity, radiological and laboratory (the analysis of blood, urine, saliva, smears and biopsy material, myography, rheography, etc.) methods of investigation.
The objective methods of investigation are used, while going on questioning the patient as it is important to know subjective sensations. For example, whether the patient feels pain in probing, percussion, etc.
External survey of the patient. After questioning survey of the face is started which is made imperceptibly for the patient. By the end of formation of the facial and brain skull, the face of the person gets individual features. The type of the face is influenced by development of the brain skull, respiratory apparatus, masticatory apparatus or musculoskeletal system. Four types of the face are distinguished accordingly: cerebral, respiratory, digestive and muscular.
The cerebral type is characterized by strong development of the brain and skull. The high and wide frontal part of the face sharply predominates other parts therefore the face gets the pyramidal form with the basis directed up.
The respiratory type is characterized by prevailing development of the middle part of the face, therefore the facial part of the head, neck and trunk get a number of prominent features. Cavities of the nose and its sinuses are strongly developed, maxillary sinuses are great, cheekbones protrude a little. The face is diamond-shaped, the nose is strongly developed in length, its back is quite often convex
The digestive type is characterized by prevailing development of the lower part of the face. The maxilla and mandible are excessively developed. The distance between angles of the mandible is great. The ramus of the mandible is very wide, massive, its coronoid process is short and wide, chewing muscles are strongly developed. The mouth is bordered by thick lips. The chin is wide and high. Due to strong development of the lower part of the face in relative narrowness of the frontal part sometimes the face gets the characteristic form of a trapeze.
The muscular type: the upper and lower parts of the face are approximately equal, hair border is usually direct, the face of the square form.
It should be also noted that the face of the person is disproportional: there is asymmetry in the structure of the left and right side. It is accounted for the fact that the left half of the brain skull is bigger than the right one, and the left half of the face is longer, the back of the nose does not coincide with the midline, the tip of the nose is shifted aside, with distance between the external corner of the eye and the corner of the mouth is not equal on both sides of the face, the right zygomatic bone and the lower half of the maxilla are shifted to the right, the right canine fossa is deeper and narrower, the teeth of the maxilla and the lower part of the nose septum are shifted to the right.
Division of the face into three parts is widely used in clinic of orthopedic dentistry: the upper, middle and lower thirds. The upper third of the face is located between scalp border on the forehead and a line connecting eyebrows. Borders of the middle part of the face are the line connecting eyebrows, and the basis of the nose septum. The lower third of the face is a part of the face from the basis of the nose septum up to the lower point of the chin.
Division of the face into three parts is conditional as position of the points during life varies. For example, the scalp border of the head in different people is located unequally and moves with the years. The height of the lower third of the face also is changeable and depends on the kind closing and amount of the teeth preserved. Only the middle part of the face has rather stable points. Absence of constant anatomic reference points and strict functional division of various parts is of little value of the offered division of the face for regenerative orthopedics.
Anatomic formations of the lower third of the face are of greater practical value.
Expressiveness of the mental folds allows to assume presence of deep bite, distal displacement of the mandible with reduction of the vertical size of the lower third of face due to loss of the lateral teeth or their pathological abrasion. Decrease in the lower third of face is frequently accompanied by formation of perleches in corners of the mouth. Thus they become wet and have hyperemic look. Retraction of the lips speaks about absence of the frontal group of the teeth and if there is expressiveness of the nasolabial folds it is possible to draw a conclusion about complete loss of the teeth.
The establishment of such deviations on survey is evidence of sharp reduction of the interalveolar height in the lower third of the face which are interrelated with absence of teeth-antagonists.
It is important to distinguish two heights of the lower part of the face for the orthopedic purposes: height of relative rest and occlusionheight. The dentitions are not closed in height of relative rest, there is an opening between them from 1 up to 8 millimeters, depending on depth of incisal overlappings, the muscles of the face are in the condition of physiological rest. Occlusion height is characterized by tight closing of thedentitions under the condition of central occlusion, the muscles are in the contracted condition. Knowledge of these characteristics is important in construction of removable dentures.
Survey of the face also allows to establish diseases the patient had before or concomitant general somatic diseases. For example, presence of cicatrices in the area of the upper lip is evidence of operative interventions for creft. Dryness of the skin integuments, presence of the skin folds pulled together in the area of the upper and lower lip with reduction of size of the oral fissure surmises the diagnosis of systemic scleroderma. Presence of cicatrices speaks about consequences of chemical or thermal burns. The face has a characteristic form in a number of endocrine diseases, e.g. acromegaly. Presence of moustaches and beard in women is characteristic of the disease of Ischenko –Cushing.
A close survey of the face accompanied by purposeful questioning of the patient will promote a correct diagnosis both the basic and concomitant.
Inspection of organs of the oral cavity. Inspection of organs of the oral cavity is one of the basic moments as detection of local manifestations of the disease determines further tactics of orthopedic treatment.
Inspection is made in the following sequence: survey of the oral cavity, estimation of the teeth, estimation of the dentitions, presence of defects in them, interrelation of the dentitions, estimation of the mucous membrane of the oral cavity, estimation of the maxillary bones.
First of all, pay attention to a degree of opening of the mouth. Restriction of opening of the mouth is probable iarrowing of the oral aperture as a result of muscular or articular contraction and will prevent carrying out of many manipulations in prosthesis (introduction of trays for taking impressions, imposing of denture, preparation of the teeth).
Inspection of the teeth. Inspection of the teeth is made by a probe, mirror and tweezers. For convenience survey of the teeth is started with the right side of the mandible, then left with transition to the maxilla, continuing survey from the left to the right. On examination the mirror is held in the left hand, and a probe or tweezers – in the right one. The mirror enables to examine the tooth from different directions. Attention is paid to the position of the tooth, its shape, colour, condition of the hard tissues (affection by caries, fluorosis, hypoplasia, etc.), Stability of the tooth, a ratio of its extraalveolar and intraalveolar parts, position in relation to occlusion planes, presence of a filling, crown, their condition. The probe determines integrity of the crown parts, sensitivity of the tooth, depth of the gingival pocket. Simultaneously colour of the tooth is evaluated (reduction or absence of enamel shine, presence of chalk-like or brown spots, sulci). In depulpated teeth enamel has no characteristic shine, it is of a grayish-yellowish shade. The enamel happens to change in smoking, in workers connected with manufacture of acids, alkalis. The form of the teeth also changes in a number of diseases.
The important point in survey of the teeth is determinationof mobility of the tooth. There are physiological and pathologicalmobility of the teeth. The former is natural and is imperceptible to the eye. Its existence is proved by abrasion of contact points andformation of contact areas. Pathological mobilityis characterized by appreciable displacement of the tooth in small effort.
Mobility of the teeth is a sensitive indicator of the parodont condition, its supporting apparatus, that is of great importance for making the diagnosis, estimation of results of treatment or prognosis.
There are four degrees of pathological mobility of the teeth (by Entin). In the first degree displacement is in the vestribulo-oraldirection. In pathological mobility of the seconddegree the tooth is displaced in vestibulo-oral and mesiodistal directions. In the third degree the tooth, plunges in the socket on pressure and then comes back in the initial positionbesides displacement ina vertical direction. In the fourth degreeof pathological mobility the tooth has not only visiblemobility in three specified directions, but also can rotate.
Pathological mobility is always accompanied by presenceof pathological gingival pockets. Presence and their depth are determined by the probe.
Pathological mobility of the teeth is often accompanied by the expressedatrophy of the alveolar process thereforethe extraalveolar part of the tooth prevails over intraalveolar one. This is most typical of single-standing teeth. The increase in the external lever causes a functional overload of the tooth. A special preparationis requiredto use such teeth for prosthesis consisting of shortening of the crown part of the tooth.
The restored dental defect by a filling or cupping (crown) is carefully examined, paying attention to undamaged state of the filling, conformityof the artificial crown to requirements (dense adjacency of edges of the crown to the neck of the tooth, its integrity, change of colour, etc.).
Results of survey of the teeth are written down in the dental formula.Deciduous teeth are designated by Roman figures,permanent – Arabian.
Methods of percussion, probing and palpationare widelyusedwhile inspecting the teeth and making the clinical diagnosis.
Percussionis made by the handle of tweezers or dental surgery probe,slightly tapping on various surfaces of the tooth. On percussion of a healthy tooth the clear loud sound is heard and the patient does not react. In changes of the pulp, parodont there are painfulsensations of different intensity. Percussion is made cautiously, and pain in weak impact does not demand further increase in impact force.The teeth with the lost pulp, depulpated with the filled upcanals give an empty sound. Make percussion of the adjacent teethfor comparison. In extension of the periodontal fissures a muffled sound is audible. Dullness of the sound results from disorder of blood circulation in the periodont, development of edema. Edematious tissues as though absorb the sound. In the pathological process at the topof the root there is marked dullness of the sound on percussion.
Probing is applied to determine depth of the carious cavity, character of the softened tissue as well as to study the conditionof the parodont. The concept of the parodont includes a complex of the formations having genetic and functional unity: the tooth, tissues of the periodont, bone tissue and periosteum, gum. At the neck of the tooth in the gum there is a circular ligament attaching the gum to the tooth and protecting the periodont from external damages. Impaired integrity of this formation leads to inflammation, various formations along the depth of pathological gingival pockets. An angular probe with blunt end is used for determination of the pocket depth, there are millimetric divisions on its surface. The probe is introduced ingingival sulci without effort from different directions of the tooth. If the probeplunges by 1-2 millimeters it is evidence of absence of the pocket or it is called a physiological gingival pocket. In immersing of the probe fromthe anatomic neck by half of the vertical size of the crown part of the tooth or more, we speak about a degree of atrophy of the alveolus.
Presence of the pathological gingival pocket should be differentiated with false gingival pocket which is formed in inflammation and significant edema of the marginal parodont tissues and in hypertrophic gingivitis. In appropriate treatment the mucous membrane of the gums comes to norm and the pocket disappears.
In a number of diseases there is a reduction of the gingival space therefore it is at the certain levelin relation to the tooth root. In this case we speak about clinical neck of the tooth.
Palpation is applied for determination of mobility of the tooth. Mobilityof the tooth is a symptom of many diseases: parodontitis,periodontitis, acute and chronic trauma arising due to inflammatory processes and edema of the surrounding tissues.
During survey and instrumental inspection absence of the teeth is also established. Thus by questioning we find out whether the tooth was extracted orprimary edentia takes place.
Assessment of the condition of dentitions. Inspection of the dentition is made separately. We determine: 1) number of the remained teeth; 2) presence and topography of the defect; 3) replacement of defects by dentures and theirkind; 4) character of contacts with the adjacent teeth; 5) form of the dentalarches; 6) a level and position of each tooth in relation to occlusion planes; 7) a kind of bite.
In the correctly formed maxillodental systemthe dentitions representa single whole both morphologically andfunctionally. The unity of the dentitions is provided with interdentalcontacts, alveolar process and parodont.
Interdental contact points in the frontal teeth are located near the cutting edge, and in the lateral – near the chewingsurface from the approximal sides. There are triangularspaces under them turned by the basis to the alveolar process which are filled in with gingival pupillae. Thus they are protected from damage by food. Besides, the pressure falling on the teeth,is distributed not only to the root of the tooth, but also to the adjacent teeth by interdental contacts, providing unity of the dentition.
With the years contact points are obliterated and contact platforms are formed instead of them. Their abrasion is a proofof physiological mobility of the teeth. A mesial shift of the teeth takes place causing shortening of the dentition up to 1cm.There is no impairment of continuity of the dental arch.
While examining the dentitions we revealabsenceof a tooth (teeth), the cause of its loss. The tooth caot erupt because of absence of the permanentdental germ, then we speak aboutprimary or congenital adentia.If loss of the tooth has occurred after eruption, we speak about secondaryor acquired adentia.
There is a lot of variants of edentulous defects.There was offerred a classification of dentitiondefectsformed as a result of loss of the teeth.The most widespread classification in our country and abroadis that offered by Kennedy which takes into considerationposition of defect in the dentalarch and its extent. Defects of the dental arches are divides into 4 classes.
The dental archeswith bilateralend defectswhich have formedas a result of lossof chewing teethare related to the first class.
The second class is madeby the dental arches havingunilateralend defect.
The dental arches with intermediatedefectin the lateral part on one side are related to the third class.
In the fourth class only frontal teeth are absent.
If there are some defects of various classesin the dental arch, the dental arch is related to a smaller order class. For example, in the dental formula
0004300 0004560
There is a defect of the fourth and first class, in this case dentalarches are related to the first class.
In physiological norm each tooth has a certainpositionin relation to occlusion planes.Occlusion planeis a plane drawn from the cutting edge of the central incisor of the mandible to the top of the distal buccal tubercle of the second (third) molar. In orthognatic bitethe teeth are located in relation to occlusion surfaces in a certain order: cutting edges of the incisors, canines and distal buccal tubercle of the thirdmolar touch a plane, the first and the second premolars and molars are located below this plane. The central incisors and canines of the maxilla are by 2/3 mm (depth of the incisiveoverlappings) belowthe occlusion plane. Such arrangement of the teeth providescurvatureof the dental arch in anterior-posterior and lateral directions.
Defects of the dentitions not onlybreak morphologicalunity of the dentitions but also leadto its complex reorganizationin the area of the defect at first, and then extends to alldentition.This reorganization is manifested by an inclination of the teeth asidedefect, vertical moving of the teeth deprived of antagonists,turning around the axis and other impairments which result in deformation of the occlusion surface.
There are primary and secondary moving of the teeth. Primary moving begins with eruption of the teeth and comes to an endwith formation of the dental arches. It is acceptedto consider change of the positionof the teethafter their eruption andformations of dentitions as secondary movingdue to defectsof the dental arches or as result of parodontitis, tumours of the jaw,traumatic occlusion
Most often there issecondary movingof the teeth which is made in variousdirections.
The following kinds of secondarymovingare most widespread.
The first group.
1. Verticalmovingof the upper teeth unilaterallyor bilaterally.
2. Verticalmovingof the upper and lower teeth unilaterallyor bilaterally.
3. Mutualvertical displacement of the upper and lower teeth unilaterally orbilaterally.
The second group.
1. Distal or mesial displacement of the upper teeth unilaterallyor bilaterally.
2. Distal or mesial displacement of the lower teeth unilaterallyor bilaterally.
The third group.
1. Inclination of the upper teeth to the palatal or buccal side.
2. Inclination of the lower teeth to the palatal or buccal side.
The fourth group.
Turn of the tooth around of the longitudinal axis.
The fifth group.
Combined moving of the teeth.
Secondary movings of the teeth sometimes are brought to the forefront,determining character of all clinical picture, and determine relative typicalness of the therapeutic measures in different kindsof secondary movings. Hence it is important to reveal them during clinical inspection of the patient.
Estimation of the condition of the mucous membrane of the mouth.The healthymucous membraneis pale pink colour in the area of the gums and pinkin other sites. In the pathological processes colour of the mucous membrane varies, there are various elements of affection on it. The most widespread of them: erosion – superficialdefect, aphtae- small sites of ulceration of yellow-grey colourwith bright red rim of inflammation, ulcers – a primary morphological element in the form of defect with rough and undermined edges and the bottom covered with grey coating.
The patient complains of reddening of the mucous membrane, bleeding, edema and burning of the orthopedic bed mucous membrane.
The cause of the specified symptoms can be:a mechanical trauma, disorder of heat exchange of the mucous membranedue tobad heat conductivity of the plastic denture,toxico-chemical influence of plastic components, allergic responseto plastics, systemic diseases (avitaminosises, endocrine diseases, diseases of the gastrointestinal tract, mycosises, etc).
During inspection it is important to establish character of affection of the mucous membrane, the cause which has caused this affection, stages of the disease(aggravation, remission). All these factors are of great value fora choice of the method of treatment and the material of whichdentures will be made as well asdetermination of term of the beginning of prosthesis. For example,in presence of erosion, ulcers of the traumatic character, prosthesisis made after their complete cure. On detection of manifestations of lichen rubor planus, leucoplakia and other chronic diseasesinthe oral cavity, prosthesis is made during remission.
On detection of the above-stated affections of the mucous membrane of the oral cavity, it is necessary to carry out additional investigations (the analysis of blood, cytology), consult with the dentist – therapist and specialist on skin and veneral diseases if necessary for differentiation. For example, traumatic ulcers should be differentiated from cancer and tubercular ulcerations, syphilitic ulcers.
The long-term trauma may lead to hypertrophyof the mucous membrane and formation of fibromas, papillomas.
Inspection of the maxillary bones.Formations of the bone bed are simultaneously investigatedduring surveyof the mucous membraneof the oral cavity and palpation. Attention should be paid to expressivenessof the alveolar process, the arch of the hard palate, maxillar tubers.The zone of the median suture for determination of the torus is necessarily investigated.
The sharp bone ledges are sometimes determinedin the area of edentulous alveolar process which have formed as a result of incompleteobliteration of sockets of the tooth and protruded interdental septum. Theseledges are painful, as the mucous membrane covering them is thinned; it is not expedient to make prosthesis without special surgical preparation of these sites.
In some cases it is possible to establish presence of boneledges (exostoses) on the mandible on the lingual sides on the right and the lefthalf of the jaw, their significant expressiveness demands specialpreparation before prosthesis by removable denture.
Inspection of the temporomandibular joint.The interalveolar distance decreases, positionof the mandible is changed causing changed position of the articular heads and all ratios of elements of the jointin formation of defects of the dentitions due to loss of masticatory teeth, pathologicalabrasion of the remained group of the teeth, diseases of the parodont. All thisleadsto disease of the joint.
Synchronism of displacement of the articular head in relation tothe articulardisk and articular fossa in movements of the mandiblecanbe disturbed in diseases of the muscles, especially external pterygoid muscles, central nervous system, diseases of the joint (arthritis, arthrosis). Therefore during inspection it is important to reveal the original cause of the disease of the joint as the techniqueof prosthesis and character of therapeutic treatmentdepends on it.
The most frequent complaints are pains inthe joint: swelling in the joint region, difficulty in opening orclosing of the mouth, pain, clicking, headache, burningof the tongue, dryness in the mouth. A method of palpationis used to examine the joints. For this purpose the index fingers of the hands are placed at the anterior surface of the tragus of the ear and the patientis askedto openthe mouthslowly. By palpation we determine the surface of the articularhead and a the posterior zone of the articular fissure. Moving fingers forward and pressing on the projection of the articular fissure and articular head, we determine painful points. Palpation is made in the closed denttition, at the moment of opening and in widely open mouth.
Sound of friction, crepitation in the joint may be associated with impaired release of the synovial fluid. A click or a crackle at the momentof opening of the mouth is more likely caused by reduction in height of bite and distal displacement of the mandible, and, hence, articular heads.Crepitation, crackle and click is also possible to determine by the methodof auscultation by means of phonendoscope. In pains in the joint, click and crackle, it is necessary to carry out additional investigations (roentgenography, rheography, arthography).
LABORATORY AND INSTRUMENTAL METHODS OF INVESTIGATION
Laboratory-instrumental methods of investigation are consideredadditional as they are not always used. The purpose of theseinvestigations – establishment and confirmation of the exact diagnosis.
Radiological examination is based on taking andperusalof the X-ray pictures. Varioustechniquesare used for this purpose:
- Intra- and extraoral roentgenography;
- Tomography;
- Panoramicroentgenography
Roentgenographyis the most widespread andaccessiblemethod of radiological investigation of the teeth, alveolar processes, jaws, bones of the facial skeleton and skull.
Roentgenography gives valuable data of the condition of hard tissues of the crown and root, the size and peculiarities of the pulp chamber,root canals, width and character of the periodontal fissure , a conditionof a wall socket an alveolar process. With its help it is possibleto study alsoa structure jaws, mutual relation of elementsof the temporomaxillary joint and to reveal thus presence of pathological processes in the areas inaccessible to external examination, deformation of bones of the maxillofacial area.
In the X-ray picture the image is negative: the bone tissue has light shades, soft tissues, air spaces -dark. The enamel has a ligher tone than cement and dentin.Carious cavities have darkshades. The cavity of the tooth,periodontal fissures look as darklinesof various configuration.
The intraoral roentgenogramallows to determine carious cavities, retention teeth,topographyof the pulp, patency of canals, presence of denticles, condition of the periapical tissues, hanging edges of the crowns, a degree of atrophyof the bone tissue of the alveolus.
Tomography.The radiologicalresearch convenientin studying structuralchangesof the alveolar process and jaws, has appeared insufficient in examination of the temporomandibular joint asit has a difficult structure and is located near the basisof the skull. Therefore it is almost impossible.to receive the X-ray imageof the temporomandibular joint by means of usual methodsof roentgenography
Usual roentgenography of the jointgives pictures only aboutrough changes in the joint(fractures, sharp deformationsof the articular surfaces in inflammatoryand degenerateprocesses). It is impossible to reveal thin changes at the initial stages of the disease by this methodand the joint looks normal on the roentgenogram.
All this has induced search for new, more perfect ways of radiological investigation of the joint.Tomography is related to such methods. It allows to receive the X-rayimage of the certain layer of the bone located at this or thatdepth. This method enables to study interrelationof elements of the temporo-maxillary joint at certain depth. It is also possible to reveal fine structural changes in the jointboneswith its help, caused both by general and local (dysfunction, trauma) diseases.
Panoramic roentgenography (panography).Panoramicroentgenography was offered by Blackman. It allows to receive a fullpicture of all teeth in the form of a panoramic picture of sufficient sharpnesswith 2 times magnification and considerably smaller irradiation than in usual picture. The survey is made during movement of the object and cassette, and the X-ray tube remains without movement.Only those layers of the object which are taken with identicalspeed with a filmare determined. These layers are shown with greater sharpness, andthe others are greased. The X-ray tube is placed behind,below the occiput. In making a picture the armchair with a patientrotates clockwise, and the cartridge with an X-ray film- in the opposite direction.As a result a developed image of the jaws is obtained.Availability of a radiologicalmethod generated a notion of its harmlessness in some dentists. It has led to unreasonable indications to roentgenography of the teeth and alveolar process. Meanwhilethe X-ray irradiation is not harmless for an organism and it is necessary to rememberit.
On inspection of the patient before prosthesis it is necessary to make roentgenography of the teeth with affected parodontous membrane, teethwith fissures, teeth – abutments of bridge dentures, clasps, covered by crowns, teeth with pathological abrasion andteeth changed in colour, etc.
X-ray visiography.Lately there have been devised the devicescombiningX-ray installation and a videocamera, the so-called X-ray visiograph. They enable to receive the image of tissues of the tooth and soft tissues magnified 27 times onthe screen by means of a videocamera. Besides by means ofX-ray visiograph it is possible to receive a photoof the imagereceived on the screen.It distinguishes it from the usual X-raydevice as time is not required for development of the film.The image in the photois more precisethan on the X-rayfilm. X-ray visiographis placeddirectlyin the dentist’s room.
Methods of determinationof masticatory pressure.Absolute forceof chewing muscles.The chewingmusclesare related to force muscles, i.e. developing preferred force unlikeother muscles which can develop preferred velocity.
Absolute muscular force is determined by number of the tissues which are a part of the given muscle, i.e. the area of the physiologicaldiameter. The more fibers in the muscle, the moreis the areaof the physiological diameter,the greater forcethe given musclecan develop. Weber considers that “force of the muscle is proportionalto its transversal section under equal conditions”.
By Weber, a muscle with a diameter of 1 cm2develops the force equal of 10 kg.The muscles lifting the mandible have the followingdiameters of section: the temporal muscle – 8 cm2, chewing muscle – 7.5 cm2,external pterygoid muscle – 4 cm2. Proceeding from data of transversal section, absolute force of the temporal muscle is equal to 80 kg, chewingmuscles – 75 kg, external pterygoid – 40 kg, i.e. the general absoluteforce of muscles of one side is equal to 195 kg. The general absolute forceof chewingmuscles of the right and left sides makes 290 kg (195×2).
The absolute force of muscles established theoretically byaddition of indices of physiological diameters of the chewing muscles,lifting themandible, and multiplication of the received sum by possible development of force in each square centimeterof the transversal sectionsection of the muscle, naturally,does not represent the facts. In concomitant work the chewing muscles cannotdevelop the force equal to 290 kg. Absolute force both of chewing andother muscles, develops only at the moment of danger and mental shock, and in the ordinary life the person does not have necessity to develop such force in chewing food. Therefore researchersare interested in pressure which develops onthe certain site for nibbling and chewing food of definite consistence (meat, bread, crackers, etc.). It is also important to know endurance of the parodont of certain teeth to chewing pressure. It would allow to be guided in permissible load in prosthesis with bridge and other dentures.
Endurance of the parodont is measured by special devices –gnatodynamometers. A gnatodynamometer was offered for the first time in 1893by Bleck. Then other devices have been designed, based onthe same principle. The device is supplied by a platform for the teeth. In closing of the mouth the teeth transmit certain pressure tothe springthrough the platform which is registered by the scale inkg. Last years new designsof gnatodynamometry were offeredwith strain sensores.
The method of gnatodynamometry proved to be insufficiently exact asthese devices measure endurance of the parodont to the pressure havingonly one direction (vertical or lateral). In actionof force on the tooth the pressure expands and effects the abutment and adjacent teeth.
Static methods of determination of chewingefficiency.For determination of endurance of the parodont and role of eachtooth in chewing special tables are offered which receivedthe name of statistical systems of accounting of chewing efficiency. A degree of participation of each tooth in the act of chewing is determined by a constantvalue expressed in percentage.
While drawing up the specified tables the role of each tooth is determined by size of the chewing and cutting surface, amount of roots, size of their surface, distance at which they are movedfrom the jaw angle. Some tables are offered constructed bythe sameprinciple (Dushange, Vustrov, Mamlok, etc.).The static system of accounting of the chewing efficiency developed by N.I.Agapov is widely used in ourcountry.
Chewing coeeficients of the teeth by N.I.Agapov
|
Teeth |
|
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
Total |
|
Chewing factors, % |
The maxilla |
2 |
1 |
3 |
4 |
4 |
6 |
5 |
– |
25 |
|
The mandible |
1 |
2 |
3 |
4 |
5 |
6 |
5 |
– |
25 |
N.I.Agapov has accepted chewing efficiency of all dentalapparatus for 100 %, and for unit of chewing ability andenduranceof the parodont – a small incisor, comparing all other teeth with it. Thus, each tooth has constantchewing coefficient in his table .
N.I.Agapov’s has made the amendment in this table, recommending to take into consideration teeth-antagonistsin calculationof chewing efficiency of the remaining dention. For example, in the dentalformula
654001 1 100345
654001 100345
Chewing efficiency is equal to 58 %, and in the dental formula
654001 100345
000000 I 000000
it is equal to zero as there is no pair of antagonists.
As it is already noted, in Agapov’s system value of each toothis constantand does not depend on condition of its parodont. For example, the roleof the canine in chewing is always determined by the same factorirrespective of, whether it is steady or has a pathologicalmobility. It is serious lack of the offered system.
V.Yu.Kurljandsky offered a static system of the accounting of the conditionof the basic apparatus of the teeth, named a parodontogram by him.The parodontogram is received by recording data about eachtooth in the special table.
A conditional coefficient is given toeachtooth with healthy parodont in the parodontogram like in other static schemes. Thesecoefficients are made on the basis of proportional ratioof endurance parodont of different teeth to loading thatwas determined by gnatodynamometry in unaffected parodont.The coefficient of endurance of the parodont to loadingis accordingly loweredat different degrees of socket atrophy in different teeth.In atrophy of IV degree the parodont does not possessendurance to loading(the tooth is subject to extraction).
It is assumed in practice that the parodont of the tooth is able to indure twice more loading than loading in processing food.
FUNCTIONAL METHODS OF INVESTIGATION
Functional chewing tests.Static methods appearedto be poorly acceptable to determination of a disorder degree of chewing efficiency not only because theyinsufficiently preciselydetermine a role of each tooth in chewing and perception of chewingpressure but also because they do not consider a kind of bite, intensityof chewing, force of chewing pressure, influence of saliva on grinding of food, a role of the tongue in the mechanism of formation of food bolus. Therefore, there were offered functional (chewing) tests allowingto receive more correct concept about dysfunction of chewing.
Chewing force of the muscles. In physiology it is force which can be developed by all chewing muscles lifting the mandible. According to Weber’s data it is equal on an average to 390 – 400 kg (the physiological diameter of all three pairs of muscles-elevatorsof the mandible is equal to 39 cm2, and 1 cm2 of the area of the physiological diameter of the muscle can develop force of 10 kg). Hence all chewing muscles can develop force of 390-400 kg. The physiological diameter of the internal pterygoid muscle is equal to 4.0 cm2, proper chewing – 8 cm2, temporal -7.5 cm2, i.e. the internal pterygoid muscle can develop force of 40 kg, proper chewing -75, and temporal-80 kg, all in all 195 kg on one side, and 390 kg – on both.
Chewing pressure is force realized by chewing muscles on one side of food grinding. There is vertical and horizontal chewing pressure. It is measured by kgs by means of gnatodynamometer.
Chewing efficiencyis a degree of crushing food by the teeth. Chewing efficiency is measured by percentage in comparison with the intact maxillodental system which chewing efficiency is accepted to be 100 %.
Chewing test by Christiansen is thefirst of techniques for determination of chewing efficiency. He investigated a degree of crushing of certain food – a hazelnut or a coconut. 5 g of a nut were taken for the test, after 50 chewing movements the patient spat out masticated mass on a small sieve with a diameter of 2.4 mm. The mass was sifted, the leftovers were weighed. The leftovers divided by 5 g and multiplied by 100 % – made the factor of Christiansen.
Chewing test by Gelmanis a modified technique of Christiansen offered for estimation of the functional condition of the maxillodental system and determination of chewing efficiency. The test is based on the author’s supervision that the intact dentomaxillary system crushs 5 g of almond for 50 sec. till the size of the particles siftedthrougha 2.4 mm sieve. In presence of dentition defects – for 50 sec. but the almond is not completely crushed, and its part remains on the sieve.
Technique: 5 g of almond is weighed and given the patient to put in the mouth and to start chewing after a signal “begin”. The beginning of chewing is marked by a stop-watch. In 50 sec. the examined stops chewing on the signal “stop”, spits out the chewed mass in the cup, rinses his mouth and spits out water in the same cup. 5-8 drops of 5 %solution ofmercuric chloride are added for disinfection. The ontents of the cup is filtered through gauze and evaporated in water bath. Then the mass is carefully sifted through the sieve, often stirring, it is better to use a wooden stick. The part of the mass which have remained on the sieve is accurately poured onto the watch glass, and weighing is made. A percent of chewing disorder is calculated by the following formula. Suppose there was a mass of 2.62 gon the sieve, then:
5 : 2.82 = 100:X, where X-percent of chewing disorder
х: 2.82 = 100 : 5
х= 2.82х100 282:5 = 56.4 %.
Chewing efficiency makes 100 %– 5б.4 % = 43.6 %.
Chewing test by I.S.Rubinov
Itis offered for estimation of the functional condition of the maxillodental system. Various products with different physical properties are applied (a nut, a cracker, fresh bread, etc.). On the basis of the chewing test it is revealed that in deterioration of conditions of the dental system time of chewing in processing firm food substances (nut) before swallowing is extended and despite it food particles of rather big size are swallowed. It is known that in adults with a high-grade chewing apparatus duration of chewing of a nut kernel before swallowing on the average makes 14sec and the leftovers are equal to zero (by the method of Christansen), and in absence of 2-3 teeth time of chewing is equal to 23sec, and a part of the kernel remains insufficiently crushed. In cases of the intactand damaged dental system time of chewing soft food differs a little. I.S.Rubinov uses a nut kernel for test instead of 5 g almonds. It enables to judge about functional condition of separate groups of the teeth. Processing of the data received of the kernel chewing is made by S.E.Gelman’s technique.
Graphic methods of studying of themandiblechewing movements.Various diseases of the oral cavity and chewingmuscles impair biomechanics of themandible. In process ofrecoveryof the patient movements of the mandible can be normalized. Normal movements of the mandible, their impairment and dynamics of restorationcan be studied by means of a graphic method.Nowrecord of chewing movements of the mandible can be made by various devices: cymograph, oscillograph, etc.
I.S.Rubinov has been detailed record of chewingmovements of the mandible (masticationagraphy)and value of each of components of the graphic record is deciphered.
Investigation of function of the masticatory muscles.
The function of the masticatory muscles changes not only duringvariousmovings of the mandible but also due to pathologicalconditions of the chewing apparatus: loss of the teeth, diseaseof the joint, change of bite height. Therefore it is desirable to obtain data of the functional condition of chewing muscles bymyotonometryandelectromyographyfor full characteristic of the clinical picture accompanying this or that diseaseof the chewingapparatus.
The tone of the chewingmusclesis measured by means ofmyotonometry. The devices applied for this purpose refer to as myotonometres. A degree of tension (density) of the muscles we may judge of the supplied force with which a probe of the device is plunged into the selected depth. Arrows of the dial show a degree of muscle tension in grams.
Electromyography.Electromyography is measurementof biopotentials of the muscles in general and on chewing in particular. There arecurrents of actionin themduringcontraction of the muscles. These currents of actioncan be strengthened by special devices and write them down on photographic paper of the oscillograph in the form of a curve. Such methodof research is referred to as myography.
Thermodiagnosis.Detection of the tooth response to temperaturestimuli (warmth or cold) – thermodiagnosis- is one of the simplest methods of investigation of the pulp condition of the tooth. The teethwhich have nochanges in the hard tissues and pulp respond to the thermalfactorabove +50°C, to cold below +10°C. In pulpitis irrigation of the tooth by hot water of +50°C, sometimes below, or applying the tampon moistened with hot waterto the toothcauses sharp, long-termpain, and in deep caries pain is quickly over. The teeth respond to cold and hot substances after preparation, in exposure of the neck, in wedge-shaped defects.
A special device, athermoodontochronometeris used for determination of the tooth response. By means of the device the selected temperatureinfluences a certain site of the tooth. The devicesensor enables to receive temperature from 0 up to +70°C and can smoothly adjust it. The device fixes time of the response.
Diagnosis is one of the most difficult sectionsof clinicalmedicine in general and orthopedic dentisty in particular.Correct diagnosis is possible if resultsof the various investigations confirm reliability of symptoms, andthere is a clear etiology, pathogenesis of the disease,clinical course and pathological anatomy.
The dentist collects the separatefacts (symptoms) in a certain sequence, analyzes them to carry out synthesis of the factscollected.
Having received results of the various investigations confirming reliabilityof symptoms, he compares them with symptoms of knowndiseases and offers a hypothesis) or somehypotheses. There may be several working hypotheses in making a diagnosis. All of them, especially in difficult clinical cases, should be checked up carefully not to make medicalmistakes:diagnosis of one disease instead of another; diagnosis of onediseasewhereas the patient suffers from several diseases, diagnosisof complications of the basic disease without determination of the basicdisease, diagnosis of complications as a basic disease, and the basic one is treated as a complication.
Differentialdiagnosis may help in checking-up of the hypotheses .
Thus, the diagnosis should be made so that, first,to characterize the cause of the disease, i.e. etiology and pathogenesis, secondly,to give the idea of a pathoanatomical basis of the disease, its localization; thirdly, to specify a degree and characterof functional impairments, fourthly, to specify features of the course andform of the disease.
The case history.The case record (case history) or an out-patient card of the dental patient is the obligatory official andmedicaldocument with data of the examination, the diagnosis,the plan of orthopedic treatment and its performance. All data shouldbe written down consistently and fully so that any other doctor could have a notion about the patient, validity of the chosen method of prosthesis andits outcome. A young doctor starting the practice should remember that this document, reflecting dynamics of developmentof the disease, a method of treatment and its result simultaneously is the certificateof medical maturity giving evidence of the level of clinical thinking of the doctor, his working abilities.
The case record should be filled so that it was possibleto continue treatment. In other words, other dentist who will continue treatment of the patient, proceeding from the records shouldimagine precisely the clinical picture which is available before treatment, validity of the diagnosis and a technique of treatment.
The case record in some cases can play a role of the legaldocument, therefore records in it should be clear andin sufficient amount.
A SCHEME OF FILLING IN THE CASE HISTORY
I. Official data:
a)Name
b)Age
c)Occupation
d)Address
II. Complaints of the patient (chewing disorders, aesthetics, defect of crowns,mobility, increased abrasion of the teeth, pain inthe temporomandibular joint; pain under basis of the removable denture, pain inthe tooth under artificial crown, etc.)
III. Anamnesis of the disease:
1.From what age the patient started to lose the teeth and what, in what sequence (incisors, canines, premolars, molars).
2.Did the patient note association of pathology of the teeth with working conditions,life, the sustained diseases ( rickets, infectious diseases, bad habits, etc.).
3.The causes why the teeth wereextracted (destruction of the crown,mobility, increased abrasion, osteomyelitis, etc.).
4.Did the patient note development of diseasesof thegastrointestinal tract after loss of the teeth (disorder of taste, appetite, eructation, nausea, vomiting, heavy feeling in the epigastric area before and after meal, pains, etc.).
1. Whether loss of the teeth was reflected on speech.
2. Whether the patient restricted intake of foodafter loss of the teeth (substitution of hard food for softer one). Whatside he mainly chews food.
7.How care of the teeth is carried out, at what age and whether it is regular (application of a tooth-brush, powder, paste, cleans the teethonly in the evening or in the morning, before meal, after meal).
8.The patient is prosthesized for the first time or repeatedly. Does he useremovable or fixed denture (during what time, his opinion about the denture.
9.The causes of dissatisfaction with prosthesis (pains, bad fixation of removable dentures, unsatisfactory aesthetics,burning of the mucous membrane of the oral cavity under the denture,nausea, fatigue of the chewing muscles, articulation disorder, impairmentof diction, long adaptation, decubital ulcers, etc.).
10.Estimation of the old denture (aesthetics, occlusion, fixation,conditionof the artificial teeth, of the orthopedic bed tissues,of clasps, the relation to gingival edge, etc.).
11.What general diseases the patient has (anemia,allergy, stomach ulcer, duodenum, diabetes,hypertonicillness, hemiplegia, polyarthritis, bronchial asthma,neuralgiaof the trigeminal nerve, etc.)
12. Presence of bad habits (smoking, the use of alcohol).
13. Medicines the patient constantly or only recently takes.
14. Whether the patient experiences excitement, alarm before forthcomingorthopedictreatment. What causes of excitement are.
15. Whether anesthesia was given in the past in treatment or extraction of the teeth, its efficiency.
16. Peculiarities of the premorbid person (normal subject, withoutdistinct expressiveness of some features, anxious-hypochondriac, with inclination to doubts, demonstrative,hysterical, excitable passive, weak-willed, inspired, withdrawn,unsociable person).
IV. Objective data:
A) External examination.
1. Type of the face (conic, inverted conical, square, rounded).
2. Condition of integuments of the face (colour, turgor, rash, cicatrices, etc.).
3. Expressiveness of the mental and nasolabial folds(moderately expressed, smoothed out, profound).
4.Character of joining of the lips (lips are closed without pressure,are strained).
5.Corners of the mouth (lowered, are not lowered), there are/there are no perleches.
6.Position of the chin (direct, displaced aside, protrudes, sinks down).
7.Height of the lower third of the face (reduced, increased, unchanged).
B)Examination of the temporomandibular joint (TMJ).
1. A degree of opening of the mouth (free, limited).
2. A character of movement of the mandible(smooth, jerky).
3. Presence of displacement of themandible(to the right, to the left, absent).
4. Data of palpation of the mandibularheads (movement of headsis smooth, jerky).
5.Data of auscultation (crackle, crepitation, clicking)
C) Examination of the oral cavity.
1.A general characteristic of the mucous membrane of the oral cavity (colour,moisture, presence of pathological formations: polyps, cicatrices, aphthae, erosions, ulcers, etc.).
2. Salivation (plentiful, poor, normal).
3.A condition of hygiene of the oral cavity (good, satisfactory,unsatisfactory).
4.Dental formula. A kind of bite (orthognathic, straight line,biprognathic, prognathic, progenic, cross, deep, opened, fixed, unstable, a ratioof the edentulous alveolar processes of the maxilla and mandible).
5.Description of the kind of bite:
a)Signs of joining concerning all teeth, signs of joining of the anterior teeth,
b)Signs of joining of the chewing teeth in the buccopalatal direction,
c)Signs of joining of the teeth in the anteroposterior direction.
6.Inspection of the dentition
a)The form of the dentitions (ellipse, parabolic, trapezoid, flattened out, etc.),
b)Position of individual teeth in the dentition
c)Deformations of the dentition (classification by A.I.Gavrilov, Kennedy).
7.Inspection of the teeth (form, colour, condition of the hard tissues:affection by caries, hypoplasia, fluorosis, presence of fissures, their condition).
8.Examination of the parodont:
a)A condition of the gums (inflammation, atrophy),
b)Estimation of the gingival pocket (depth, pyorrhea),
c)Spread of the process,
d)Stability of the teeth,
e)A ratio of the extraalveolar and intraalveolar partsof the teeth.
9.Amount of the antagonistic pairs of the teeth.
1. The characteristic of the dentition defects (state, localization,form, size).
2. Condition of the edentulous alveolar process of the maxilla:
a)Character and degree of atrophy (uniform, nonuniform,big, small, medium),
b)A kind of the vestibular slope of the maxilla (flat,steep, with a canopy),
c)Presence of bone ledges on the alveolar process afterextraction of the teeth (localization, extent, depth of undercut, morbidity of the bone ledges on pressure),
d)The form of the crest of the alveolar process in the anterior and lateral parts (peaked, rectangular, truncated cone,semioval, flattened, a wide crest, a narrow crest),
e) Presence of the loose crest (localization, size,a degreeof displacement),
f)Expressiveness of the maxillar tubers (the form of the vestibularand distal surfaces, on the right, on the left).
12.The characteristic of a relief of the hard palate:
a)The form and height of the hard palate (the high arch, low,medium, wide, narrow),
b)A condition of the suture of the hard palate (concave, convex, flat),
c)Palatine torus (form, size, localization),
d)The form of distal edges of the hard palate (vaulted, flat).
13.The characteristic of the mucous membrane of the orthopedic bed onthe maxilla:
a)A pliability of the mucous membrane of the hard palate,
b)Expressiveness of buffer zones,
c)Expressiveness of transversal palatine folds in the anterior partof the hard palate
d)Expressiveness of the palatine blind apertures, their localization (onthe line “A”, ahead of the line “A”, behind the line “A”),
e)Incisive papilla (size, pliability),
f)The location of the transitive fold in relation tothe alveolarprocess (at the basis, at the level of slope, at the top),
g)A degree of expressiveness, the form and place of the bridle attachment of the upper lip, anterior and lateral buccal-alveolar streaks of the mucous membrane (at the basis, to the slope of the maxillar tuber,upper tuber, to aponeurosis of the muscle of the soft palate).
14.The condition of the bone basis of the orthopedic floor of the mandible:
a)Character and degree of atrophy of the alveolar process (uniform, non-uniform, big, small, medium),
b)The size, form and localization of exostoses,
c)Presence of mental torus (size, form),
d)Expressiveness of the internal slanting lines, their form (sharp,pointed, rounded), morbidity on pressure,
e)Presence of bone formations on the alveolar process afterremoval of the teeth (localization, form, size,sensitivityto pressure),
f) The form of the crest of the alveolar process in the anterior and lateralparts of the mandible(peaked, rectangular, trunkated cone, semi-oval, flattened, wide crest),
g) Presence of the loose crest on the mandible (localization, size, a degree of displacement).
15.The characteristic of the mucous membrane of the orthopedic bed on the mandible:
a)The location of the transitive fold in relation tothe alveolar process (at the basis, at the level of slope, at the top),
b)A degree of expressiveness, the form and place of the bridle attachment of the lower lip, tongue, anterior and lateral buccal-alveolarstreaks of the mucous membrane (at the basis, to the slope, to the topof the alveolar process),
c) Presence of folds of the mucous membrane of the alveolar process (the arrangement, direction, get smoothed out, do not get smoothed out),
d)Mucous tubercles (the form, size, mobility,consistency, tenderness on palpation).
1. The size and form of hypoglossal space (on the right, on the left).
2. The size and form of the hypoglossal space in the anterior partof the mandible (big, small, in the form of fissure,of the triangularform, trapezoid).
3. Submaxillary salivary glands (presence, their position in movements of the tongue: protrude over the crest of the alveolar process, do not protrude).
4. The size and tonus of the tongue (enlarged, not enlarged, the tonus is moderate, increased).
5. Tonus of the muscles of the floor of the oral cavity, cheeks and lips moderate, increased, lowered).
V.Data of special methods of examination:
1.The radiological characteristic of the teeth and periodontal tissues
(a condition of hard tissues of the crown and root, the size andpeculiarities of the tooth cavity, root canals, width and characteristic ofthe periodontal fissures, a condition of the compact plate, a wall of the alveolus and spongy substance of the alveolar process,presenceof foci of chronic inflammation, etc.)
1. Data of radiological examination of the TMJ.
2. Data of tomography and cephalometry.
3. Data of studying diagnostic models of the jaws.
VI. The diagnosis and differential diagnosis.
The diagnosis is made on the basis of data of clinical examination of the patient, which should consist of the basic and accompanying one.
1. The basic disease and its complications:
a) What basic disease has inducedthe patientto refer toorthopedic clinic;
b) Complications and impairments whichare associated pathogeneticallywith the basic disease.
2.Concomitant diseases which are treated by dentists of other sections of dentistry. Differentialdiagnosisis made if necessary.
3.In the diagnosis “Partial loss of the teeth” it is necessary to specify a kind of dental defectby Keneddy, and “Full loss of teeth”- typeof the edentulous jaw by I.M.Oksman.
VII. A plan of preparation of the oral cavity to prosthesis:
1. General sanation measures (removal of dental deposit,treatmentof the teeth, removal of the roots and teeth with mobility of III degree, treatmentof diseases of the mucous membrane of the oral cavity, etc.).
2. Special preparation of the oral cavity (depulpated teeth,eliminationof occlusion impairments, orthodonticpreparation, alveolotomy, excision of cicatricies, transfer of the placeof bridle attachment, streaks of the mucous membrane, deepening of the thresholdof the mouth, floor of the oral cavity, etc.).
VIII. A plan of the orthopedic course.
Specify what kind of prosthesis (immediate, nearest,remote). Substantiate a choice of the denture construction.
IX. A diary of orthopedic treatment.
All references of the patient are written down with the indication of date andthe detailed description of the given clinical procedures. In repeatedreferences of the patient after application of the denture the complaints,given objective investigation, character of the rendered aid and features of the patient’s adaptation to a denture are described. Make assessment of the nearestresults of prosthesis (quality of the denture, functional properties, a condition and reaction of orthopedic bed tissues, amountof corrections, a response of the patient, etc.).
X.Epicrisis and prognosis of orthopedic treatment.
First, middle, last name, age and complaints of the patient on the dayof reference to clinic are written down, the diagnosis made, the beginning and termination of treatment, a kind of prosthesis and a denture construction.
A condition of the patient as a result of the treatment given andprognosis are described.
|
Stages of work, equipment |
The technique of work. |
Elements of self-control. |
|
Examination of the patient Examination set |
taking the anamnesis, external survey, instrumental examination of organs of the oral cavity |
|
.
