Masseter

A strong muscle responsible for elevating the jaw during chewing.

The masseter is one of the main muscles of mastication, or chewing. It is located at the side of the jaw and plays a pivotal role in the process of grinding and crushing food. The muscle consists of two parts: the superficial part, which has fibers that run vertically, and the deeper part, which has fibers that run horizontally. This dual structure allows for both powerful jaw closure as well as fine movements necessary for effective chewing.

Terminologia Anatomica

musculus masseter

System

Muscular system

Function

The primary function of the masseter is to facilitate mastication by elevating the mandible, resulting in the closure of the jaw. During the act of chewing, the masseter contracts to bring the upper and lower teeth together, allowing food to be crushed and broken down into smaller pieces for easier swallowing and digestion. Additionally, the masseter works in conjunction with other muscles of mastication like the temporalis and pterygoid muscles to allow for lateral movement of the jaw, enabling a side-to-side grinding motion that is essential for processing certain foods. The strength of the masseter also plays a critical role in activities that require jaw exertion, such as talking and singing, effectively linking digestion and communication.

Location

The masseter is located in the lower part of the face, extending from the zygomatic arch, which is the bony prominence of the cheek, down to the angle of the mandible, or lower jawbone. It is situated laterally to the jaw and is easily palpable when a person clenches their jaw. The masseter's position makes it visible and prominent; it forms a significant portion of the muscle mass on the side of the face, contributing to the overall contour of the jawline. When observed from the front, the robust shape of the masseter can be seen accentuated in individuals with well-developed musculature, often signifying strength.

Did You Know?

The masseter is one of the strongest muscles in the human body relative to its size, capable of exerting a force over 400 pounds (approximately 180 kilograms) of pressure during clenching.
In some cultures, masseter hypertrophy (enlargement) is considered a sign of beauty or health, leading to the practice of jawline enhancement.
The masseter muscle plays a role in creating the characteristic sound of grinding teeth, known as bruxism, which can lead to dental issues if uncontrolled.