Gomphosis

A gomphosis, also known as a dentoalveolar syndesmosis, is a joint that binds the teeth to bony teeth sockets in the maxillary bone and mandible.

The fibrous connection between a tooth and its socket is a periodontal ligament.

Specifically, the connection is made between the maxilla or mandible to the cementum of the tooth.

The motion of a gomphosis is minimal, though considerable movement can be achieved over time—the basis of using braces to realign teeth. The joint can be considered a synarthrosis.

The gomphosis is the only joint-type in which a bone does not join another bone, as teeth are not technically bone.

In modern, more anatomical, joint classification, the gomphosis is simply considered a fibrous joint because the tissue linking the structures is ligamentous.

It has been suggested that this permanent soft-tissue attachment was a critical requisite in the evolution of the mammalian (synapsid) tusk.

A gomphosis is a specialized fibrous joint in which a conical process or peg of one bone fits into a hole or socket in another bone. (gomphos is a Greek word meaning bolt).

Small quantity of fibrous tissue holds the bones together. No movement is possible at such peg-and-socket joints.