Full Masseter Muscle Description
[Continued from above] . . . lateral surface of the ramus of the mandible.
The second part, the deep portion, is a lot smaller and has a texture that is more muscular. This part comes from the posterior third of the lower border and by way of the whole of the medial surface of the zygomatic arch. The fibers go down and forward and fit into the top half of the ramus and the lateral surface of the coronoid process of the mandible. This portion of the masseter muscle is only partially covered by the superficial portion in front. It is concealed by the parotid gland behind. The fibers of both the deep and superficial portions are continuous at their insertion.
The masseter lifts the mandible and assists in protracting it. The nerve comes from the mandibular nerve. The name for this muscle means the chewer muscle.