Anatomy

Origin

Zygomatic process of maxilla, medial and inferior surfaces of zygomatic arch. Superficial division: arises by a thick, tendinous aponeurosis from the temporal process of zygomatic bone, and from the anterior two-thirds of the inferior border of the zygomatic arch. Deep division: it is much bigger, and more muscular in texture. It arises from the posterior third of the lower border and from the whole of the medial surface of the zygomatic arch.

Insertion

Angle and ramus of mandible, lateral surface of coronoid process of mandible. Superficial division: Its fibers pass inferior and posterior, to be inserted into the angle of the mandible and inferior half of the lateral surface of the ramus of the mandible. Deep division: Its fibers pass downward and forward, to be inserted into the upper half of the ramus as high as the coronoid process of the mandible.

Nerve

Mandibular division of trigeminal nerve

Actions

Elevates mandible (rotation at temporomandibular joint) closing mouth, biting