Tooth Anatomy & Histology
Dentition
Comprise layers of calcified tissues surrounding a cavity that houses neurovascular structures.
Key Features
Regions
- The crown, which lies above the gums.
- The neck, the constricted area.
- The root, which lies within the alveoli (aka, sockets) of the jaw bones.
- Pulp cavity lies in the center of the tooth, and extends into the root as the root canal.
- Neurovascular structures pass through the apical foramen to reach the pulp cavity.
Layers
- Dentin: comprises calcified organic matrix and inorganic hydroxyapatite crystals; this makes the dentin similar to, but harder than, bone.
- Cementum: covers dentin in the neck and root regions; is anchored to the surrounding periodontal membrane by ligaments (not shown, here).
- Enamel: covers the crown of the tooth; it comprises enamel rods (aka, prisms), and is the hardest material in the body.
Bony attachments
- Sockets = alveoli
- The periodontal membrane (aka, ligament) lies between the tooth and the bone
- Gingiva epithelium covers bone (gingiva refers to the gums)
- Gingival sulcus is the small space between the gingiva and the neck of the tooth. This space is enlarged in periodontal disease.
Images:
Histology (Mark Braun, MD, & Indiana University: http://medsci.indiana.edu/c602web/602/c602web/toc.htm; http://www.indiana.edu/~anat215/virtualscope2/start.htm)