elevates and wrinkles skin of chin, protrudes lower lip
The mentalis is a paired central muscle of the lower lip, situated at the tip of the chin. It raises and pushes up the lower lip, causing wrinkling of the chin, as in 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.