The mouth, the oral cavity is topographically divided into so-called threshold of the mouth and oral cavity (Fig.). The term "mouth" refers also mouth enclosed lips of the mouth. The borders of the vestibule of mouth are in front of the lips and cheeks, and behind alveolar processes of the jaws and teeth. Oral cavity above is limited to the arch palate; the basis of floor of mouth is oral sublingual muscle located over her chin-speaking, chin-sublingual, sublingual-speaking muscles. The back border of the mouth presents the soft palate, and the contraction of the muscles which a hole throat, limited also the root of the tongue and front velopharyngeal temples. Swallowing the soft palate separates the oral cavity and oral part of the throat from the nose.
Fig. 1-3. The oral cavity. Fig. 1. Sagittal section. Fig. 2. Front view (mouth corners cut). Fig. 3. frontal section:
|1 - palatum durum (solid sky);
2 - dentes (teeth);
3 - labium sup. (upper lip);
4 - rima oris;
5 - labium inf. (lower lip);
6 - vestibulum oris (ahead of the mouth);
7 - mandibula;
8 - m. mylohyoideus;
9 - m. genlohyoideus;
10 - gl. sublingualis;
11 - m. genloglossus;
12 - os hyoideum;
13 - isthmus faucium (Zev);
14 - lingua (language);
15 - palatum molle (soft palate);
16 - cavum oris proprium;
17 - frenulum labii sup.;
18 - LC gingival (gums);
19 - arcus palatoglossus (neben-speaking shackle);
20 - tonsilla palatine (neben amygdala);
21 - uvula (tab);
22 - frenulum labii inf.;
23 - arcus palatopharyngeus (velopharyngeal shackle);
24 - plicae palatinae transversae;
25 - venter ant. m. digastrici;
26 - m. buccinator;
27 - corpus adiposum buccae.
The oral cavity is lined with mucous membrane, in the thickness of which is a large number of minor salivary glands. The mucous membrane of the mouth is covered with multi-layer flat epithelium, which is located on the basis of connective tissue. This layer without sharp boundary goes into the submucosa. In the gums, tongue, lateral parts of the hard palate and the region palatal seam submucosal layer is missing. Blood, lymph flow and innervation of the walls of the mouth cavity is closely connected with the vascular and nervous systems of the jaws (see). In the mouth open ducts of the salivary glands.
You should indicate changes in the structure of the oral mucosa with age: there comes a thinning of the epithelium, showing signs of its degeneration, violates the integrity of the basal membrane, connective tissue becomes denser. Marked lengthening venous parts of capillaries, reducing their number, slowing down of blood flow. The surface epithelium cells with increasing age, the tendency to keratinization. All these changes have a significant impact on the emergence and development of the pathological process, and must be considered during the examination or treatment of the patient.
The mouth - the initial division of the digestive tract. Here the food is subjected to mechanical and partially chemical treatment (see Chewing). In the mucous membrane contains a number of receptors, which are determined by taste, tactile and pain sensitivity. Pain and temperature sensitivity of the mucous membranes of the oral cavity reduced in comparison with skin and is different in different areas.
In the mouth contains diverse microbial flora: in addition to regular adapted, microbes, here a long time may be present microorganisms brought from outside. In this regard distinguish between permanent and casual microflora of an oral cavity, and the constant microflora is a biological barrier for the microbes that get in the oral cavity from the outside.
With decreasing the resistance of the body can manifest pathogenic properties of some microbes usually vegetating in the mouth. Prolonged use of antibiotics may also violate the biological barrier and to facilitate the emergence of "drug" lesions of the mucous membrane. Agents of diseases of a mucous membrane are often fungi of Candida, enterococci and gram-negative bacteria. Frequent fungal damage mucous membrane in aspergillosis, the sporotrichosis and others, and also at actinomycosis, blastomycosis.
Among diseases of mucous membrane of the most often causes gingivitis (see) and stomatitis (see). The disease can occur at avitaminosis, blood diseases, after taking some medicines (bismuth, mercury, lead). In some infectious diseases (measles, scarlet fever) develop specific defeat mucous membrane of the oral cavity. The oral cavity diseases include diseases of the teeth, jaw, tongue, lips, salivary glands (see Cialdini, Sialolithiasis).
Particularly noteworthy are the so-called precancerous: hyperkeratosis (see), leukoplakia (see), papilloma (see).
Among mechanical damage of mucous membranes should be borne in mind ulcers resulting from long-term injuries to the teeth and dental prostheses (decubital ulcers).
To benign tumors observed in the oral cavity are cyst (see), epulis (see), fibroma (see), lipoma, angiomas. Malignant tumors are cancer and sarcoma - are observed less often they occur more often in the field of language and sky. Sometimes the tumor originating from the jaw bones protrude on the eve or the mouth.
Cm. also, the Teeth, the Sky, the Language.