HEAD AND NECK

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HEAD AND NECK

• DR VINIT K ASHOK
• ADJUNCT FACULTY

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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----PROTECT
  IVE
• SOME AREAS SHOW KERATIN

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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
• PALATEFORMS THE ROOF OF THE MOUTH/SEPERATES THE
  ORAL AND NASAL CAVITIES
• 2 PARTS-----HARD/ SOFT
• HARDLIES ANTERIORLY MADE OF BONE. FOOD IS PUSHED
  BY THE TONGUE AGAINST IT
• SOFT---LIES POSTERIORLY, MADE OF MUSCLE. CLOSES
  THE NASOPHARYNX DURING SWALLOWING

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ORAL CAVITY

• TONGUE-
• OCCUPIES FLOOR OF THE MOUTH
• MADE UP OF SKELETAL MUSCLE
• FUNCTIONS
• REPOSITIONS FOOD BETWEEN THE TEETH
• MIXES FOOD WITH THE SALIAVA, FORMS BOLUS
• PUSHES THE BOLUS INTO THE PHARYNX DURING
  SWALLOWING
• SPEECH
• CONTAINS TASTE BUDS
• POSTERIOR PART CONTAINS LINGUAL TONSILS

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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

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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

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MILK TEETH
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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

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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

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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

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SALIAVARY GLANDS
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SALIAVARY GLANDS
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SALIAVARY GLANDS