The orbicularis oris is a circular muscle around the mouth that closes and compresses the lips. It is not a sphincter muscle, but consists of numerous strata of muscle fibres, having different directions, which surround the orifice of the mouth.
The points of origin and insertion, and the actions of the orbicularis oris muscle:
|Locations on the mandible (lower jaw bone) and maxillae (upper jaw bones)
|Strictly the mucous membrane of the margin of lips, although some texts merely state the 'lips' or the 'skin around the lips'
The orbicularis oris is sometimes referred to colloquially as the 'kissing muscle' because its actions include puckering the lips. It is also used by muscicians playing brass instruments (e.g. the cornet, trombone and tuba) and some woodwind instruments. This muscle is also used to close the mouth.
The orbicularis oris is one of the muscles of the head, neck, and face taught as part of many courses in Indian Head Massage. As this is a popular therapy we have included several pages that may be of interest to students of Indian Head Massage. See, for example, the page about skeletal structures of the head and neck.
See the page about Facial Muscles to view the location of the orbicularis oris muscle. (This page consists of an interactive, rather than just a labelled, diagram, so you'll have to test yourself by guessing which muscle is the orbicularis oris until you find the correct label.)
More about Muscles:
- The structure of muscle tissue and the structure of muscle cells
- Labelled diagrams of the muscles in different parts of the body including anterior muscles, posterior muscles and facial muscles
- Various other pages about e.g. types of muscle contractions, movements at joints, muscular disorders and related topics such as books about sports medicine
- Anterior Muscles
- Posterior Muscles
- Facial Muscles
- Muscle Terminology (Definitions)
- 1. Structure of Muscle
- 2. Structure of Muscle Cells
- 3. Muscle Filaments
- 4. Sliding Filament Theory
- 5. Neuromuscular Junction
- 6. Actions at Neuromuscular Junction
- Types of Muscle Contractions
- Muscular Disorders
- Effects of exercise on muscles