Oral cavity – normal anatomy.

Plan and rules of case history registration. Anatomical and hystologycal construction of mucous membrane of oral cavity.

 

 

Oral cavity – normal anatomy. Structure of oral mucouse membrane.

The oral cavity sits at the opening of the digestive tract and is bounded by the lips anteriorly (Fig. 1.1). The vermillion zone serves as the transition area between the moist oral mucosa and the skin of the face. The oral structures are adapted to serve a variety of functions, including maintenance of a protective barrier, initia­tion of digestion, special taste sensation, speech and swallowing, immunologic defense, and provision of salivary lubricants and buffers.

1.2   Surface Landmarks

 

The oral cavity can be subdivided broadly into three areas consisting of the vestibule, oral cavity proper, and oropharynx (Fig. 1.2). The vestibule is the space that is present between the lips or cheeks lat­erally and the dentition medially. The oral cavity proper lies inside the dental arches and is bounded posteriorly by the anterior pillar of the fauces, or palatoglossal arch. The oropharynx lies posterior to the palatoglossal arch, and includes the posterior one-third of the tongue, palatine tonsils, soft palate, and visible posterior wall (Fig. 1.3). The palatine tonsils sit in an alcove between the anterior (palato-glossal) and posterior (palatopharyngeal) arches, or pillars, and frequently exhibit surface pits or depressions called crypts (Fig. 1.4).

The retromolar trigone is a roughly triangular area behind the last molars representing the poste­rior aspect of the vestibule (Fig. 1.5). Adjacent to this is the pterygomandibular raphe, which indi­cates the junction between the buccinator and supe­rior constrictor muscles, and is used as a landmark for administration of intraoral local anesthesia. The parotid papilla, which houses the opening of

Stenson duct of the parotid gland, is located in the buccal vestibule opposite the maxillary second molar (Fig. 1.6).

 

 

 

 

 

Folds of mucosa in the midline maxillary and man­dibular labial vestibules can be seen anchoring the lips to the alveolar mucosa or gingiva, and are known as the labial frenula (Figs. 1.7 and 1.8). These can be quite prominent in some cases and even affect tooth eruption.

 

Oral Mucosa

The lining of the oral cavity serves a variety of func­tions, including protection, sensation, and secretion, and is histologically adapted to the unique environ­ment inside the mouth. Oral mucosa lacks the appendages seen in skin, although sebaceous glands can be found in the upper lip and buccal mucosa in approximately 75% of adults (see Chap. 2). Submucosal minor salivary glands are found throughout the oral cavity, with highest concentra­tions in the palate and lower lip. Aggregates of lym-phoid tissue can also be found in the oral cavity, however, the largest collection of lymphoid tissue is seen posteriorly and known as Waldeyer ring.This consists of the palatine, lingual, and adenoid (pha-ryngeal) tonsils, and virtually encircles the entrance to the oropharynx. Small nodules of accessory tonsil tissue are often seen on the posterior wall of the oropharynx and may become enlarged with inflam­mation or infection and mistaken for a suspicious mass. Normal pits and depressions in tonsil tissue (tonsillar crypts) may become plugged with keratin or other debris and form cysts which appear yellow to white in color (Figs. 1.4 and 1.9). The majority of the oral cavity is lined by soft, moist, pliable, nonkeratinized mucosa which is loosely attached to underlying tissues and exhibits some mobility. This

 consists of a stratified squamous epithelium which con­tinually renews itself by division of progenitor cells in the deeper basal layer (Fig. 1.10). New cells show pro­gressive maturation as they migrate to the surface lay­ers, which are subsequently shed. Areas of the mouth that receive a greater degree of masticatory stress, namely the hard palate, tongue dorsum, and gingiva, are lined with keratinized mucosa, giving more protection against friction and abrasion This tissue is more firmly attached to the underlying periosteum, which prevents damage from shearing forces.

The mucogingival junction, where the mobile mucosa lining the vestibule and floor of mouth joins the tightly adherent gingiva of the dental alveolus, should be easily visible in the healthy state. The gingiva appears paler pink secondary to decreased visibility of underlying blood vessels through the relatively opaque keratin layer. The gingival margin should be well defined with slightly rolled margin and pointed interdental papillae. Healthy tissue will exhibit stippling, representing collagen fibers attaching the gingiva to the underlying perios­teum (Figs. 1.7, 1.8, and 1.11).

 

Fig. 1.10 Normal stratified squamous epithelium. The basal cells are cuboidal and abut the basement membrane. The shape becomes more flattened (squamoid) as the cells mature and move toward the surface. Irregularly shaped spinous, or prickle, cells are present in the intermedi­ate layers. Surface keratin keratin is also present in this diagram. The connective tissue layer below the basement mem­brane contains blood vessels, lymphatics, fatty tissue, fibrous and elastic tissues, bone, and muscle

 

 

Tongue

The tongue is divided into the oral tongue (anterior two-thirds) and tongue base (posterior third) by the circum-vallate papillae, which form a v-shaped line anterior to the foramen cecum (Fig. 1.12). The foramen cecum is a shallow depression which exists as a developmental remnant of the thyroglossal duct. The oral tongue is typically subdivided into four areas: tip, lateral sur­faces (sides), dorsum (top), and ventral (undersurface).

Embryologically, the mucosa lining the anterior portion of the tongue arises from the first branchial arch, and carries with it the trigeminal nerve. The mucosa of the tongue base arises from the third arch and is innervated by the glossopharyngeal nerve. The intrinsic muscles of the tongue are derived from the occipital somites, and are supplied by the hypoglos-sal nerve. Lingual tonsil tissue is frequently seen on the surface of the tongue posterior to the circumval-late papillae and lining the vallecula, which is a val­ley-like depression separating the tongue base from the epiglottis. Mucus glands are present posteriorly, and open into the crypts of the lingual tonsil.

The epithelium lining the tongue dorsum is spe­cialized to withstand masticatory trauma as well as receive taste sensation. The dorsum dorsum has an irregular, bumpy, surface secondary to the presence of papil­lae. Although some taste receptors (taste buds) can be found in the soft palate and pharynx, the majority are located on the lingual papillae. Numerous small, hair-like, keratinized, filiform papillae cover the anterior surface of the tongue dorsum and do not contain taste receptors. These projections provide an abrasive surface that helps break down food against the hard palate during mastication. They are interspersed with fewer numbers of larger, smooth, and more rounded nonkeratinized fungiform papil­lae, with taste buds present on their superior sur­face. The fungiform papillae frequently appear deeper red in hue compared to the filiform papillae,as the color of the underlying vascular core is transmitted prominently through the epithelium (Fig. 1.13). Foliate papillae are ridge-like structures on the posterolateral aspect of the tongue containing taste buds on their lateral surfaces, and are often mistaken for abnormal tissue on oral exam. . They vary greatly in size, and are virtually absent in some patients (Fig. 1.14). The circumvallate papillae are large round structures on the posterior tongue dor-sum which also house taste buds. These are usually not appreciated on exam unless the tongue is pro­truded, and are also sometimes mistaken for pathol­ogy (Fig. 1.13).

 

The lateral and ventral surfaces of the tongue, as well as the floor of mouth, are lined by thin, smooth, nonkeratinized mucosa that is fairly translucent (Fig. 1.15). Veins along the ventral surface of the tongue are easily visualized through the mucosa and can be quite prominent. A fringed fold of mucosa, called the plica fimbriata, sits lateral to the midline on each side and frequently contains tissue tags that can be mistaken for pathology. The sublingual salivary glands can be palpated laterally and frequently will be seen to bulge into the floor of mouth. The main sublin­gual duct joins the submandibular (Wharton) duct to empty into the oral cavity at the sublingual papilla near the base of the lingual frenulum. Additional tiny ducts open from the sublingual gland directly into the over­lying mucosa.

 

Palate

 

The palate forms the roof of the oral cavity and is divided into the hard palate anteriorly and the soft palate posteriorly (Figs. 1.16 and 1.17). The muco-periosteum of the hard palate is tightly bound and immobile, which explains why dental injections into this area are especially painful. The midline incisive papilla anteriorly indicates the opening of the incisive canal, which transmits the sensoryneurovascular bundle exits its bony fora­men under the mucosa opposite the maxillary sec­ond molar, innervating the posterior hard palate. The maxillary tuberosity can be palpated posterior and lateral to this behind the last molar, as the broad posterior extent of the maxilla.

 

 

 

 

 

Dentition

The tooth containing portion of the oral cavity is divided into maxillary and mandibular dental arches (Fig. 1.18). These are each further divided in half by the midline into quadrants. The teeth sit within the raised, alveolar (tooth bearing) bone of the dental arches. The adult, or secondary, dentition consists of 32 teeth, with 3 molars, 2 premolars (“bicuspids”), 1 canine (“eye tooth” or “cuspid”), and 2 incisors per quadrant. Molars and premolars are referred to as posterior teeth; canine and incisors are anterior. The pediatric, or primary, dentition contains a total of 20 teeth, with 2 molars, 1 canine, and 2 incisors per quad­rant. The premolars erupt into the space occupied by the primary molars, and the permanent molars erupt posterior to this as the jaws and dental arches elongate with growth. There are a variety of numbering systems used to identify each tooth. The most widely accepted method numbers the teeth from “1” to “32,” beginning with the upper right third molar (tooth #1) and proceeding clockwise across the upper then lower arches, ending with the lower right third molar (tooth #32).Each tooth consists anatomically of a root and crown, with the crown being the portion visible above the gingival margin (Fig. 1.19). The bulk of the tooth is made up of a calcified substance known as dentin, with an outer surface layer of harder enamel covering the crown and a softer material called cementum lining the root surface. The hollow inner core of the tooth, or pulp chamber, contains a soft jellylike material referred to as pulp, with nerve endings and blood vessels entering through the tip (apex) of the root via the apical foramen.The clinically visible junction of crown and root is called the cementoenamel junction, and is generally protected by the free upper edge of the gingival margin in the healthy state. Gingival recession may occur, with exposure of the softer root surface and concomitant increased risk of root surface caries, abrasion, or sensi­tivity. The tooth is anchored to the bony socket by col­lagen fibers (periodontal ligament), which can be weakened or destroyed by periodontal disease.The crown of every tooth has five surfaces, and each one is specifically named. The biting surface of a posterior tooth is referred to as the occlusal surface. The more tapered biting, or incising, sur­face of an anterior tooth is called the incisal edge. The outer, or lateral, surface of a posterior tooth adjacent to the cheek is referred to as buccal. The same surface of a more anterior tooth adjacent to the lip is labial. Alternatively, any buccal or labial surface may also be referred to as the facial sur­face. The inner, or medial, surface of a lower tooth abutting the tongue is lingual, and the same surface of an upper tooth facing the palate is palatal. The contacting surfaces of adjacent teeth are called interproximal; with the posteriorly oriented sur­face (i.e., away from midline) being distal, and the more anteriorly oriented surface (toward midline) being mesial.

 

Temporomandibular Joint

The temporomandibular joint (TMJ), where the foot­ball-shaped condylar process of the mandible articu­lates with the glenoid fossa of the temporal bone, is a synovial joint, and is located immediately anterior to the external auditory canal (Fig. 1.20). A roughly biconcave fibrocartilage disk (meniscus) is positioned within the joint space, dividing it into upper and lower cavities and allowing both hinge and gliding move­ments. The joint is enclosed by a fibrous capsule, and surrounding ligaments limit excessive joint move­ment. Dislocation of the jaw occurs when the man­dibular condyle moves anterior to the articular eminenceThe initial 10-15 mm of mouth opening occurs by hinge-like rotation of the condyle against the articular disk in the inferior joint space without movement of the disk itself or movement in the upper joint space. With wider mouth opening, the superior surface of the disk then glides anteriorly downward along the articular eminence, carrying the condyle along with it. This second

type of movement is referred to as translation. This sequence is then reversed with jaw closure.

Internal derangement of the joint can occur with destruction or detachment of the disk, in which case the disk may be displaced or dislocated (usually ante­riorly, in front of the condyle). In patients with this problem, a “click” may be present upon mouth open­ing as the condyle moves forward during translation and spontaneously recaptures the disk. This is referred to as reduction of the disk, and a reciprocal click may be noted with closure as the condyle again moves posterior to the disk. In a situation where reduction does not occur, the disk can become jammed anterior to the condyle and limit the degree of mouth opening; in severe cases this can result in a

closed lock with limitation of mouth opening.

 

 

Innervation.

Table 1.1  Cranial nerves

Number        Name    Function(s)

I                               Olfactory      Sense of smell

II                            Optic            Vision

III                         Oculomotor  Eye movement (except that mediated by lateral rectus and superior oblique muscles)

IV                        Trochlear      Eye movement (mediated by superior oblique muscle)

V                           Trigeminal    Oral/facial sensation; muscles of mastication

VI                        Abducens     Eye movement (mediated by lateral rectus muscle)

VII                     Facial           Facial sensation and taste (anterior tongue); muscles of facial expression and stapedius; and

secretomotor innervation to salivary glands (except parotid)

VIII                  Vestibulocochlear      Hearing and balance

IX                        Glossopharyngeal      Sensation and movement of pharynx; taste to posterior tongue; and secretomotor innervation

to parotid gland

X           Vagus           Main sensory and motor innervation to larynx and pharynx; taste sensation from epiglottis;

and parasympathetic supply to thoracic and abdominal viscera

XI                        Spinal accessory       Trapezius and sternocleidomastoid muscles

XII                     Hypoglossal Tongue movement

Jaws and Teeth

As first branchial arch derivatives, the maxilla and mandible are supplied by the trigeminal nerve (CN 5), which is predominantly sensory (Fig. 1.21; Table 1.1). The trigeminal (semilunar or Gasserian) ganglion is located in the floor of the middle cranial fossa and gives rise to three large nerve trunks. The ophthalmic division (V1) travels to the eye via the superior orbital fissure. The maxillary division (V2) passes through the foramen rotundum into the pterygopalatine fossa, where it receives sensory input from the maxillary alveolar bone, upper teeth, hard palate, and mucosa via the posterior and anterior superior alveolar nerves, nasopalatine nerve, and greater palatine nerve. The mandibular division (V3) exits the skull base through the foramen ovale, passes through the infratemporal fossa, and provides sensory innervation to the lower jaw via the inferior alveolar nerve (IAN), buccal nerve, and mental nerve. The IAN is encased within the bone of the mandible below the roots of the poste­rior mandibular teeth and is subject to injury during third molar (wisdom tooth) extraction.

 

 

 

Salivary Glands

There are three sets of paired major salivary glands: sublingual, submandibular, and parotid (Figs. 1.23 and 1.24). The sublingual gland is the smallest, and rests on the mylohyoid muscle in the anterolateral floor of mouth immediately under the mucosa. The secre­tions of this gland are primarily mucinous, and are therefore more viscous than saliva produced by the parotid and submandibular glands. The submandibular gland is larger and occupies the submandibular trian­gle with extension of the gland over the posterior bor­der of the mylohyoid muscle into the floor of mouth. The secretions from this gland are mixed seromuci-nous, with viscosity intermediate between those of the sublingual and parotid glands.The parotid gland is the largest of the three major salivary glands and is located in front of the ear (preauricular region), with extension to the posterior belly of the diagastric muscle inferiorly and the masseter muscle anteriorly (Fig. 1.24).The “tail” of the gland extends posteriorly under the earlobe to the sternocleidomastoid muscle (SCM). The gland is divided into superficial and deep lobes by the plane of the facial nerve (CN 7), with extension of the deep lobe to the parapharyngeal space medially. Tumors of the deep lobe may result in visible bulging within the oral cavity in the region of the tonsil, and may present as the first sign of pathology. Lymph nodes are present within the parenchyma of the parotid gland, mainly in the superficial lobe, due to incorpo­ration of lymphoid tissue into the gland during fetal development. These may present clinically as masses secondary to reactive or neoplastic processes. The parotid gland produces serous saliva, which is thin and watery compared to secretions from the other salivary glands.

There are hundreds of submucosal minor salivary glands present throughout the oral cavity (except for the gingiva and anterior hard palate), with a high den­sity notable on the soft palate and posterolateral hard palate. Secretions from these glands are purely muci-nous and represent a very small proportion of total salivary flow.

 

Innervation to the salivary glands is supplied by the autonomic nervous system, with both sympathetic and parasympathetic components. The parasympathetic sys­tem regulates fluid and electrolyte secretion, while the sympathetic system governs protein synthesis and secre­tion. The parotid gland receives parasympathetic secre-tomotor fibers from the glossopharyngeal nerve (CN 9), which synapse in the otic ganglion and then travel with the auriculotemporal branch of V3. Parasympathetic supplied from the superior cervical ganglion via the external carotid artery.

 

 

Case History

 

A detailed account of the facts affecting the development or condition of a person or group under treatment or study, especially in medicine, psychiatry, or psychology.

 

Parts:

CASE HISTORY

 

The patient:

The clinical diagnosis: 

The begining of treatment:

The end of treatment:

 The curator of III cours Student:

 

 

I.      General information about patient.

Surname and name:

Sex:

Age:

Education:

Place of employment, profesion:

Permanet adress:

Date and time of admision to the hospital:

The diagnosis at admision time:  

–     Clinical diagnosis:

–     Complication of primary disease:

 

 

2.     Patients complains.

3.     History of disease.

4.     Patient history life.

5.     General patient condition.

6.     External examination of facial region.

7.     Intraoral examination.

8.     Differential diagnosis.

9.     Clinical diagnosis.

10.   Etiology and pathogenesis of disease.

11.   Clinical conclusion.

12.   Treatment plan.

13.   Prescription.

14.   Diary:

15.   Epicrisis.

16.   Literature

 

 

Dental chart

 

To full dental chart we use Palmer Notation Method.

This tooth numbering system is simplicity itself – the mouth is divided into 4 quadrants (upper left, upper right, lower left, lower right), and teeth are numbered 1-8 going from the front tooth to the wisdom tooth in each quadrant.

 

Ministry of Public Health of Ukraine		Medical documentation Form №043/о By order of MOPH of Ukraine 14.02.2012          №110
Name of the clinic:
Dental chart №____ _____________year
First name, last name:
Male                                                Female
Birth date:
Address:
Home phone:
Diagnosis:
Patient complains:
General diseases:   Allergy:
Objective examination:

 

 

 

C – caries, F – filling, A – absent(missing) tooth, P – pulpitis, Pt – periodontitis, Cr – tooth crown, r – root, Dc – dental calculus

 

 

Bite:
Oral hygiene condition:
Condition of oral mucouse:
X-ray results:
VITA – color:
Date of oral hygiene training:
Date of oral hygiene control:
Doctors notes:
Date:	Anamnesis, diagnosis, treatment and recommendations:

 

Doctor_________________

Chief of department___________________

 

 

 

References:

1.   Danilevskiy M.F. et al. “ Diseases of the mucous membrane of the mouth.” – K.: “Medytsyna”, 2010.

2.   Bruch J.M. Clinical oral medicine and pathology/ J.M. Bruch, N.S. Treister// London.:Humana Press, 2010

3.   Cawson R. E. Cawson’s essentials of oral pathology and oral medicine. Seventh edition/ Cawson R. E. et. al. //Elsevier science limited, 2002.

4.   Slootweg P. Dental pathology – a practical introduction/ P.J. Slootweg// Berlin.: Springer, 2007.

5.      Da Silva J.D. Oxford American Handbook of Clinical Dentistry (Oxford American Handbooks in Medicine) / J.D. Da Silva et al.// Oxford University Press, 2007.

 

 

 

Information prepared by Sukhovolets I.O.