HEAD AND NECK

DR VINIT K ASHOK

ADJUNCT FACULTY

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

SALIAVARY GLANDS

LARGEST PAROTIDMUMPS

DUCT OF PAROTIDOPENS AT UPPER 2ND MOLAR TOOTH

SUBMANDIBULARLIES ALONG THE MEDIAL SURFACE OF MANDIBLE

SUBLINGUAL LIES INFERIOR TO THE TONGUEIN THE FLOOR OF THE ORAL CAVITY