Introduction
Every tooth has its own shape, but all share the same basic parts and the same small set of bumps and hollows. Learning that vocabulary once makes every tooth easier to describe, carve and restore.
Tooth size
Average sizes come from measuring large numbers of extracted teeth. Tables give overall length, crown and root length, crown width mesiodistally and faciolingually, and width at the cervix. Students draw and carve teeth at three times these sizes (3:1).
Crown and root: anatomic or clinical?
The cervical line, or cement-enamel junction (CEJ), separates the enamel-covered anatomic crown from the cementum-covered anatomic root. That never changes. What shows in the mouth depends on the gingiva.
- Clinical crown: the part you can see above the gingiva.
- Clinical root: the part hidden below the gingival margin.
In a healthy adult the gingival margin follows the cervical line and hugs the neck of the tooth. Soon after eruption part of the enamel is still covered, so the clinical crown is shorter; after recession part of the root is exposed, so the clinical crown is longer.