|Muscles of the head and neck.|
|Dissection, showing salivary glands of right side. (Masseter visible at center.)|
|Gray's||subject #109 385|
|Origin||zygomatic arch and maxilla|
|Insertion||coronoid process and ramus of mandible|
|Nerve:||masseteric nerve (V3)|
|Action:||elevation (as in closing of the mouth) and retraction of mandible|
In human anatomy, the masseter is one of the muscles of mastication.
It is particularly powerful in herbivores to assist when they are chewing plants.
Origin and insertion of the two heads
The masseter is a thick, somewhat quadrilateral muscle, consisting of two portions, superficial and deep.
The fibers of the two portions are continuous at their insertion. The masseter muscle is sometimes the target of plastic jaw reduction surgery.
The deep portion is much smaller, 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
Its fibers pass downward and forward, to be inserted into the upper half of the ramus and the lateral surface of the coronoid process of the mandible.
The deep portion of the muscle is partly concealed, in front, by the superficial portion; behind, it is covered by the parotid gland.
Muscles of the head, face, and neck.