Hi, everyone! This is Matt from Kenhub, and in this tutorial, we will discuss the origin, insertion, innervation, and function of the masseter muscle.
The masseter muscle or musculus masseter is a thick rectangular muscle of mastication. It consists of a superficial part… and a deep part. The muscle can be easily palpated at the mandibular ramus from the oral cavity along the cheek.
The superficial and deep parts both originate from the zygomatic arch. The superficial part inserts on the masseteric tuberosity at the outer surface of the mandibular angle whereas the deep part runs further dorsally to the outer surface of the mandibular ramus.
Furthermore, part of the deep fibers radiates into the anterior capsule and articular disc of the temporomandibular joint.
The parotid gland lies on the lateral side of the masseter with its duct coursing underneath the zygomatic arch across the muscle.
As all muscles of mastication, the masseter is supplied by a branch of the mandibular nerve, the masseteric nerve.
The masseter is one of the four muscles of the masticatory apparatus. It elevates the mandible causing a powerful jaw closure. The contraction of the superior part which runs diagonally to the front moves the mandible forward, which is known as protrusion.
Furthermore, the muscle helps stabilize tension of the articular capsule of the temporomandibular joint.