Oral Anatomy: Module 3

Teeth and surrounding structures

Tooth

A hard calcified tissue found in the jaws of many vertebrates for mastication

Functions of teeth

Mastication, shaping of the face, speech, protection, prehensile

Crown

A part of the tooth visible in the mouth

Anatomical crown

part of tooth covered by enamel from cervix to the tip of the crown

Clinical crown

Part of the tooth visible in the mouth and exposed to oral fluids; where gingiva line starts

Root

Lower 2/3 of the tooth and it is inserted in the socket

Anatomical root

Part of tooth covered by cementum from cervix to apex of root

Clinical root

Part of tooth still implanted and surrounded by cementum

Cervical/cervix line

Line of separation between the crown and root portions; cementoenamel junction

Enamel

Hard calcified tissue covering the dentin of the anatomical crown; 96-98% calcified and translucent and is permeable in young individuals

Dentin

Forms the main bulk of the tooth and surrounds the pulp cavity; covered by enamel of the anatomical crown and is 65-70% calcified; highly elastic and more radiolucent than enamel

Cementum

Layer of bony hard tissue; protects the anatomical root dentin and is 45-55% calcified; lacks luster

Pulp/pulp tissue

Uncalcified portion of tooth made up by blood vessels, cellular substances and nerves

Coronal pulp

House in the crown

Radicular pulp

In the root canal; funnel-shaped, wide at the neck and narrows apically

Functions of the pulp

Nutritive, formative, defensive, protective, and sensitive/sensory

Pulp cavity

Funnel-shaped; entire central cavity of a tooth which contains the pulp

Pulp canal

Portion of pulp cavity located at the root of the tooth

Pulp chamber

Enlarged portion of pulp cavity lying at the central portion of the anatomical crown

Pulp horns

Elongations or extensions of pulp chamber often corresponding to the pulp or lobes of the tooth

Periodontium

Keeps tooth in position in the socket; supporting and investing tissue of the teeth (gingiva)

Periodontal ligament

Regularly arranged dense fibrous connective tissues in the periodontal space; ligaments surrounding the root of the tooth made up of fibers that supports the tooth in the alveolus

Free gingival ligament

Holds the gingiva firmly to tooth and are fibers running form cementum to neck cementum of tooth to connective tissue supporting the gingiva

Transeptal/interdental

Running from cementum of the mesial surface of one tooth to cementum on the distal of adjacent tooth

Interdental

Between teeth

Proximal

Mesial to distal

Alveolo-dental

Cementum to the walls of alveolus; from neck of tooth to chest of alveolar bone

Alveolar crest group

Neck to crest of bone

Horizontal group

Cementum to the bone horizontally

Oblique group

Cementum to bone coronal direction

Apical group

cementum at root apex to wall of alveolus

Interradicular group

Found in between the roots

Alveolar bone/alveolar process

calcified connected tissue which is an extension of mandible and maxilla forming the sockets where the roots of the teeth are anchored; 65% calcified and supports and encloses the tooth

superficial cortical plate of bone

forms wall or lining of the socket; table 1

alveolar bone proper

where fibers are attached; table 2

Spongiosa or cancellous bone

between table 1 and 2

Gingival unit

only dental tissue that can be seen clinically with the naked eye; made up of epithelial tissues covered with mucosa

Free gingiva

freely mobile and not attached to the underlying structures

marginal gingiva

extends along the cervical level of tooth; knife-like edge

interdental papilla

fills up space between the teeth

free gingival groove

separates the free gingiva from attached the gingiva (if 3mm)

Attached gingiva

part of gingiva attached to bone