DENTAL ANATOMY BY DR MANISHA MISHRA Oral Cavity

DENTAL ANATOMY BY DR. MANISHA MISHRA

Oral Cavity l Entrance of the gastrointestinal tract l Dental arch: alveolar arch of the maxilla and mandible l 4 types of teeth l Incissor l Canine l Premolars l Molars

Boundaries l l l Anterior: Lips Posterior: anterior tonsillar pillars (palatoglossal folds) Lateral: cheeks Roof: palate Floor: anterior 2/3 of tongue

Parts l Oral vestibule l Space between the lips and teeth/gingiva l Oral cavity proper -

Functions l l l Speech Respiration Digestion Chewing Aesthetic

Landmarks l l l l Frenulum Mucobuccal fold (posterior) Mucolabial fold( ant ) Canine eminence Parotid papilla ( stenson’s duct ) External oblique ridge Retromolar trigone

Landmarks on roof Incisive papilla: covers the incisive foramen between 2 incissors l Palatine rugae l Uvula l

Landmarks on the floor Tongue l Lingual sulcus l Frenulum l

Anatomy of tooth Anterior teeth: Incissors and canine l Posterior teeth: Molars and premolars Each tooth consists of: l Crown – The part which protrudes from the gum l Root – Part embedded in the bone l Neck – Slightly narrowed region where the crown merges with root l

Components of tooth Pulp containing neurovascular bundle l Dentine l Enamel l Cementum l

enamel Hardest tissue l Surrounds dentine l highly mineralised Main mineral- hydroxyapatite l

dentine Dentine is the most abundant dental tissue l Determines the size and shape of teeth. l Dentine is a bone-like substance that is formed by odontoblast cell which makes up most of the structure of the tooth. l Dentine is found just under the enamel in the crown and under the cementum in the root. . l

pulp Connective tissue, mainly consits of odontoblast and fibroblast l Contains neurovascular components l There is anastomosis between arterioles & venules l

cementum Cementum is a specialized bony substance covering the root of a tooth l Cementum is excreted by cells called cementoblast within the root of the tooth l Its color is yellowish and it is softer than either dentine or enamel. l Alveolar Bone l Mineralized tissue that surrounds the teeth in jaws

Periodontal ligament The periodontal ligament is a specialized connective tissue that attaches a tooth to the jaw bone Function l Helps tooth withstand large compressive forces which occur during chewing, without destruction of the adjacent alveolar bone l to serve as a source of sensation. (outer covering of the tooth (enamel) has no sensory receptors itself. ) l

gum l l Mucous-membrane-covered connective tissue attached to and surrounds the neck and the alveolar bone. Edges of the gums around the teeth are free and extend into the spaces between the teeth. healthy gum is pink and tough. have limited sensitivity to - pain, Temperature, pressure

Blood supply Periodontal plexus l Inferior/superior alveolar vessel l Periosteal vessel l Vessel from adjacent musculature l

Nerve supply Upper teeth – maxillary nerve (Ant. Sup. Alveolar, middle sup. Alveolar & post. Sup. Alveolar nerves) l Lower teeth – mandibular nerve (inferior alveolar nerve) l

Mandible Only moving bone present in skull, Has sockets for lower teeth l Parts – Body & 2 Rami Body – l 2 surfaces – External & Internal l & 2 borders – Upper (Alveolar), Lower(Base) Ramus l 2 Processes – Coronoid & Condyloid

Mandibular Foramen - opening on the medial surface of the ramus l Oblique Line - located on the superior lateral surface of the body l Mental Foramen - foramen for the transmission of the mental nerve (cutaneous to the lower third of the face) and artery l

The mandible is the body support for the mandibular teeth l And is also the insertion for the four primary muscles of mastication and the accessory muscles of mastication. l It is the movable portion of the TMJ articulation with the temporal bone l

The Muscles of Mastication - The chief muscles of mastication are: l Masseter. l Medial Pterygoideus l Lateral Pterygoideus l Temporalis. Nerve l Mandibular division of Trigeminal Nerve

1. Mandibular Condyle 2. Mandibular Notch 3. Coronoid Process 4. Ramus 5. Angle 6. Oblique Line 7. Body 8. Alveolar Process 9. Mental Foramen 10. Mylohyoid Line 11. Mandibular Foramen

maxilla The maxilla is a fusion of two bones along the palatal fissure that form the upper jaw l has sockets for upper teeth l

Parts l Body l Four processes l The zygomatic process l The frontal process l The alveolar process l The palatine process

NOMENCLATURE l DECIDUOUS 1. 2. 3. 4. 5. DENTITION: Central incisior=A Lateral incisior=B Canine=C 1 St Decidious molar=D 2 nd Decidious molar=E

Deciduous dentition

l PERMANENT 1. 2. 3. 4. 5. 6. 7. 8. DENTITION: Central incisior=1 Lateral incisior=2 Canine=3 1 st premolar=4 2 nd premolar=5 1 st permanent molar=6 2 nd permanent molar=7 3 rd permanent molar=8

Permanent dentition