Muscle · Head

Levator anguli oris

Musculus levator anguli oris

A deep strap running from a hollow in the upper jaw just below the eye socket down to the corner of the mouth, where it lifts the corner up and inward. It lies beneath the two muscles that raise the upper lip, so it is the deepest of the smile muscles on that side of the face and cannot be felt separately from them. Its fibres end in the same fibrous knot at the corner of the lips that the mouth-corner depressor pulls on from below — the two are direct opponents across a shared anchor. It arises immediately below the infraorbital foramen, and the infraorbital nerve — the sensory nerve of the cheek, upper lip and side of the nose — emerges there and passes forward superficial to it.