Orbicularis oris

A complex muscle that encircles the mouth, vital for various facial movements.

The orbicularis oris is a muscle that forms a circular shape around the mouth. It is classified as a sphincter muscle, meaning it can constrict and open the mouth. This muscle is primarily responsible for movements related to facial expression, such as pouting and kissing, as well as playing a significant role in speech and mastication by controlling the position of the lips.

Terminologia Anatomica

musculus orbicularis oris

System

Muscular system

Function

The orbicularis oris muscle plays multiple crucial roles in the body, particularly in facial expression and oral function. Its primary function is to regulate the opening and closing of the lips, allowing for precise movements necessary for speech. The control of the mouth's movements is essential for articulation, as various sounds require the lips to assume specific shapes. Additionally, this muscle helps maintain food within the oral cavity during chewing, thus aiding in the process of digestion. The orbicularis oris also assists in facial expressions associated with emotions, conveying feelings such as happiness, sadness, or anger through variations in lip posture. Overall, it acts as a key communicator, linking physical actions with emotional expressions.

Location

The orbicularis oris is located at the lips of the mouth, encircling them in a circular formation. It lies beneath the skin and is attached to the surrounding facial muscles. Anatomically, it stretches from the maxilla (upper jaw) to the mandible (lower jaw), providing a connection in both directions. As a superficial muscle, it is readily accessible and can be palpated easily beneath the skin, making it an integral part of the facial musculature. Its proximity to other facial muscles allows it to work in concert with them during various expressions and oral functions.

Did You Know?

The orbicularis oris is sometimes referred to as the 'kissing muscle' due to its role in puckering the lips.
This muscle can be involuntarily activated during reflexive actions, such as when tasting something delightful.
Different cultures have distinct ways of using the lips, affecting how the orbicularis oris is engaged during communication.
Individuals can exhibit varying degrees of control over this muscle, which impacts their ability to articulate speech and express emotions.