Located in the face, the orbicularis oris muscle controls movement in the mouth. Specifically, it encircles the mouth, originating in the maxilla and mandible bones. The muscle inserts directly into the lips. For innervations, the muscle relies on the seventh cranial nerve, as well as the buccal branch of the facial nerve. In common language, the orbicluarlis oris is often referred to as "the kissing muscle." It allows for facial expression, and specifically, it is responsible for puckering the lips. While this action is a requirement for kissing, the puckering action is also used in a number of other ways. For example, the lips must contract into a pucker to forcefully exhale, which is necessary for playing certain music instruments such as trumpets and other horns. The obicularis oris muscle is also responsible for closing the mouth. In the past, the muscle was thought to be a sphincter. Recently, it has been found to not exactly meet that definition, even though it does perform sphincter-like opening and closing actions.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Orbicularis oris