What is the function of the muscle orbicularis oris?

The orbicularis oris is a circular muscle around the mouth, primarily responsible for movements involving the lips. Its main function is to facilitate actions such as pouting, kissing, and shaping the lips during speech. This muscle allows for the compression and movement of the lips, leading to various expressions and behaviors related to the oral region.

The correct understanding focuses on how the orbicularis oris plays a crucial role in actions involving the lips rather than moving the mandible, elevating the corners of the mouth, or facilitating blinking, which are functions associated with other muscles in the facial region. For instance, compressing the cheeks is primarily the function of the buccinator muscle. Thus, the orbicularis oris specifically contributes to lip movements rather than jaw movements.