| Latin | Musculus orbicularis oris |
|---|---|
| Origin |
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| Insertion |
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| Action |
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| Nerve | Facial nerve (CN VII), buccal branch (the lower lip also receives the marginal mandibular branch) |
| Name | Latin orbiculus, 'small circle', and os, oris, 'mouth' — the ring muscle around the mouth. |
Palpation
- Client supine; sit at the head of the table.
- Place one or two finger pads lightly on the skin just above the upper lip or just below the lower lip.
- Feel the soft band of muscle running around the mouth under the skin.
- Ask the client to purse the lips as if to whistle; feel the ring tighten under your fingers.
The orbicularis oris surrounds the mouth and makes up most of the lips. It looks like a ring, but it is not a true circular muscle: it is made of four quadrants that interlace, together with fibres from many surrounding face muscles such as the Buccinator and Zygomaticus. Those surrounding muscles pull the lips in different directions (for example, zygomaticus draws the corner up into a smile), and orbicularis oris brings them back together.
In Head, face and scalp — 20 min massage, use light strokes from the centre of the upper lip out to the corners, then the same below the lower lip, finishing with small circles at the corners of the mouth. Clients who clench their jaw or press their lips together when stressed often find this relaxing. Keep off the lips themselves, and use little or no product around the mouth.
Sources differ slightly on the nerve supply. Wikipedia lists only the buccal branch of the facial nerve, while many anatomy texts add the marginal mandibular branch for the lower lip. Both are branches of the facial nerve (CN VII).