Muscles of Mastication

Muscle - Temporalis
Origin - Temporal fossa
Insertion - Coronoid process and ramus of mandible
Nerve - Trigeminal
Action on Mandible - Elevates; retracts

Muscle - Masseter
Origin - Lower border and medial surface of zygomatic arch
Insertion - Lateral surface of coronoid process, ramus and angle of mandible
Nerve - Trigeminal
Action on Mandible - Elevates (superficial part); retracts (deep part)

Muscle - Lateral pterygoid
Origin - Superior head from infratemporal surface of sphenoid; inferior head from lateral surface of lateral pterygoid plate of sphenoid
Insertion - Neck of mandible; articular disk and capsule of temporomandibular joint
Nerve - Trigeminal
Action on Mandible - Depresses (superior head); protracts (inferior head)

Muscle - Medial pterygoid
Origin - Tuber of maxilla (superficial head); medial surface of palatine bone (deep head)
Insertion - Medial surface of angle and ramus of mandible
Nerve - Trigeminal
Action on Mandible - Elevates; protracts


The jaws are opened by the lateral pterygoid muscle and medial pterygoid muscles.