Head and Neck Anatomy: Part II – Musculature
Mentalis

The mentalis muscles are a pair of muscles located centrally in the lower jaw. The origin attaches to the inferior border of mandible on either side of the midline. The insertion is into the skin of the chin below the lower lip. Its action is hard to understand but basically raises the skin over the chin and elevates central portion of the lower lip. It also pulls the tissue under the lip causing protrusion of the lip as in a pout.