Mandible

Function

The only mobile skull bone. Carries the lower teeth, transmits the bite force of the muscles of mastication through the TMJ, and shapes the lower third of the face. Its movements include hinge opening, protrusion and lateral grinding.

Landmarks

• Body
• Ramus
• Angle (gonion)
• Condylar process (head)
• Coronoid process
• Mandibular notch
• Mental foramen
• Mandibular foramen
• Symphysis menti

Articulations (joints)

• Temporal bones (temporomandibular joints)
• All lower teeth in alveolar sockets

Clinical relevance

The angle is the commonest mandibular fracture site. The inferior alveolar nerve runs inside the body — fractures cause lip numbness. Dislocated TMJs lock open after wide yawning.