The Masseter muscle is a powerful muscle located in the human jaw. It is responsible for controlling the movement of the jaw and is an important muscle for speaking, chewing, and swallowing.
Structure
The Masseter muscle is a broad, triangular muscle that originates from the zygomatic arch (a bony structure in the cheek) and inserts onto the mandible (lower jaw). It has a thick, fleshy belly and is divided into two parts: the superficial part and the deep part.
The superficial part of the Masseter muscle is the larger and more visible portion of the muscle. It is located just under the skin and extends from the zygomatic arch to the angle of the mandible. The deep part of the Masseter muscle is located deeper in the tissue and extends from the zygomatic arch to the coronoid process of the mandible (a bony protrusion on the front of the mandible).
Location
The Masseter muscle is located in the face, specifically in the region of the jaw. It is a paired muscle, meaning that there is one on each side of the face. The Masseter muscles are located just below the cheekbones and extend from the zygomatic arch to the angle of the mandible.
Function
The primary function of the Masseter muscle is to control the movement of the jaw. It is responsible for closing the jaw and bringing the mandible towards the skull. This movement, known as jaw closure or mastication, is essential for speaking, chewing, and swallowing.
The Masseter muscle is also important in facial expression. It helps to raise the corners of the mouth during a smile and can contribute to the appearance of a square jawline.
Clinical significance
The Masseter muscle is an important muscle for maintaining proper jaw function. Dysfunction of the Masseter muscle can lead to problems with speaking, chewing, and swallowing. Masseter muscle spasm or hypertrophy (enlargement) can also cause facial pain and discomfort.
In some cases, Masseter muscle hypertrophy can lead to an appearance of a square or bulging jawline. This condition, known as Masseteric hypertrophy, can be treated with injectable botulinum toxin (Botox) to weaken the muscle and reduce its size.
