The mentalis is a paired central muscle of the lower lip, situated at the tip of the chin. It pull down on the margin of inferior orbicularis and everts the central portion of the lower lip. In conjunction with orbicularis contraction, the mentalis muscle allows the lips to "pout." Externally, mentalis contraction causes wrinkling of the chin skin, as used in expressions of doubt or displeasure. It is sometimes referred to as the "pouting muscle."
Its fibers arise from the incisive fossa of the mandible, then course vertically downward to insert in the skin of the chin.