The movement of a tooth back into the bone is called what?

• A. Intrusion
• B. Extrusion
• C. Open Bite
• D. Overbite

Answer: (A)

Intrusion is the apical movement of a tooth, pushing it back into its socket within the jawbone. This term specifically describes moving a tooth deeper into the bone, which is the opposite of extrusion—where a tooth moves toward the chewing surface and partly out of the socket. Open bite and overbite describe how the upper and lower teeth relate vertically when biting, not a direction of tooth movement. In practice, intrusion is used to correct teeth that have overerupted or to adjust the bite by moving a tooth deeper into the alveolar bone.