The masseter is a prominent muscle located in the jaw area of mammals, including humans. It is one of the main chewing muscles and plays a crucial role in the mastication process by elevating and closing the jaw. The name "masseter" is derived from the Greek word "massein," meaning to chew.
Anatomically, the masseter is a thick, quadrilateral muscle that covers the sides of the jawbone, originating from the zygomatic arch (cheekbone) and inserting into the mandible (lower jawbone). It consists of two main parts: the superficial masseter and the deep masseter. The superficial masseter is larger and more visible, while the deep masseter lies beneath it.
The masseter muscle works in coordination with other muscles involved in chewing, such as the temporalis, to exert the force required for biting and grinding food. It contracts when the mouth is closed, bringing the lower jaw upward to meet the upper jaw, while releasing tension when the mouth opens. This muscle is exceptionally strong, allowing for the necessary force to break down food into smaller particles for swallowing and digestion.
In addition to its primary function in chewing, the masseter can also contribute to facial expressions. It may be involved in clenching or grinding the teeth, a behavior commonly associated with stress or anxiety.
Due to its functional importance and proximity to the temporomandibular joint (TMJ), the masseter muscle can be subject to various conditions such as muscle pain, spasms, or disorders affecting the jaw's movement.
