ORAL CAVITY
• ALSO CALLED THE MOUTH. MUCOSA LINED.ENTRY INTO THE ALIMENTARY CANAL
• BOUNDARIES- ANTERIORLY-LIPS LATERALLY-CHEEKS SUPERIORLY-PALATE INFERIORLY-TONGUE
ORAL CAVITY PROPER---LIES INTERNAL TO THE TEETH
EPITHELIUM ---THICK STRATIFIED SQUAMOUS----PROTECTIVE
SOME AREAS SHOW KERATIN
ORAL CAVITY
• LIPS-( LABIA) + CHEEKS KEEP THE FOOD INSIDE THE MOUTH DURING MASTICATION( CHEWING)
• BOTH HAVE SKELETAL MUSCLES• LIPS----ORBUCULARIS ORIS• CHEEKS---MAINLY THE BUCCINATOR MUSCLE
PALATE—FORMS THE ROOF OF THE MOUTH/SEPERATES THE ORAL AND NASAL CAVITIES
2 PARTS-----HARD/ SOFTHARD—LIES ANTERIORLY MADE OF BONE. FOOD IS PUSHED BY
THE TONGUE AGAINST ITSOFT---LIES POSTERIORLY, MADE OF MUSCLE. CLOSES THE
NASOPHARYNX DURING SWALLOWING
ORAL CAVITY
• TONGUE-• OCCUPIES FLOOR OF THE MOUTH• MADE UP OF SKELETAL MUSCLE FUNCTIONS
1. REPOSITIONS FOOD BETWEEN THE TEETH
2. MIXES FOOD WITH THE SALIAVA, FORMS BOLUS
3. PUSHES THE BOLUS INTO THE PHARYNX DURING SWALLOWING
4. SPEECH
5. CONTAINS TASTE BUDS
6. POSTERIOR PART CONTAINS LINGUAL TONSILS
SWALLOWING
• FOOD IS TAKEN INTO THE MOUTH( INGESTION)
• IT IS PUSHED INTO THE PHARYNX BY THE TONGUE( VOLUNTARY PHASE ) OF DIGESTION.
• PROPULSION IS THE INVOLUNTARY MOVEMENT OF FOOD THROUGH THE ALIMENTARY CANAL DUE TO “ PERISTALSIS”
TEETH
• LIE IN SOCKETS( ALVEOLI)
• UPPER ROW---LIE IN THE MAXILLA
• LOWER ROW---LIE IN THE MANDIBLE
• HELP IN MECHANICAL DIGESTION OF FOOD
• TWO SETS DEVELOP IN HUMANS---
• 1) DECIDOUS( MILK) TEETH)
2) PERMENANT TEETH
MILK TEETH
TEETH START FALLING BETWEEN 6-12 YRS
DENTAL FORMULA2102 21022102 2102
6 MONTHSLOWER CENTRAL INCISOR
TOTAL OF 20 TEETH DEVELOP AT INTERVALS
PERMENANT TEETH
• TOTAL OF 32
• ALL EXCEPT THE WISDOM TEETH ( LAST MOLAR) APPEAR BY THE END OF ADOLESCENCE
• WISDOM TEETH APPEAR BETWEEN 17-25 YRS
TOTAL 32
SOMETIMES LAST MOLAR DOES NOT APPEAR
2I, 1C, 2P, 3M 2I, 1C, 2P, 3M X2= 32
INCISORS, CANINE, PREMOLARS,MOLARS
TOOTH STRUCTURE
• 2 REGIONS-CROWN /ROOT• BOTH MEET AT THE NECK• ENAMEL COVERS THE
CROWN• BULK FORMED ---DENTINE• PULP CAVITY-CENTER• ROOT CANAL- PART OF THE
PULP CAVITY IN THE ROOT• ROOT –COVERED BY
CEMENTUM• PERIODONTAL LIGAMENT
HOLDS THE TOOTH IN PLACE
TOOTH STRUCTURE/ DISEASE
• INCISORS- CHISEL SHAPED- NIPS PIECES OF FOOD• CANINE-CONE SHAPED-TEAR AND PIERCE• PREMOLARS( BICUSPIDS)-GRINDING• MOLARS-GRINDING• DENTAL CARIES- LOSS OF ENAMEL AND DENTIN DUE TO
BACTERIA• DENTAL PLAQUE-SUGAR , BACTERIA AND OTHER DEBRIS
ADHERING TO TEETH• GINGIVITIS- INFLAMMATION OF THE GUMS
SALIAVARY GLANDS
PRODUCE SALIAVA
MOISTENS, DISSOLVES AND PROVIDES TASTE
CONTAINS LYSOZYME,ANTIBODIESANTIVIRAL AND CYANIDE LIKE COMPOUND
CONTAINS PROTEINS
SALIAVARY GLANDS
GLANDS
INTRINSIC( SMALL)KEEP THE MOUTH MOIST
EXTRINSIC( LARGE)POUR SECRETIONS -DUCT
PAIRED GLANDSPAROTID, SUBLINGUAL
SUBMANDIBULAR