Here is the action of each muscle affected respectively: (1) Frontalis - Draws scalp anteriorly, raises eyebrows, and wrinkles skin of forehead horizontally, (2) Orbicularis Oculi - Closes the eye, (3) Orbicularis Oris - Closes and protrudes lips; compresses lips against teeth, and shapes lips during speech, (4) Buccinator - Presses cheeks against teeth and lips; draws corner of mouth laterally, and assists in mastication (chewing) by keeping food between the teeth (and not between teeth and cheeks), and (5) Platysma Muscles - Draws outer part of lower lip inferiorly and posteriorly; depresses the mandible