Masseter is one of the most powerful muscles for its size in the body. It originates in the lateral part of the cheek bone (zygomatic arch) and inserts in the angle of the mandible. It acts to raise the jaw and clench the teeth. This muscle functions to chew food and derives its name from the Greek for chewing, and is associated with angry and aggressive states. When this muscle is chronically too tense, the abnormal condition called "Temporal-Mandibular Disorder," also known as TMJ, can occur.

Masseter is innervated by the masseteric nerve of the mandibular division of the trigeminal nerve (V) and is supplied with blood by the superficial temporal, maxillary, and facial arteries.

Action of Masseter

 

A Human Face