medial band m. nasolabialis connects the upper lip to the back of the septum of the nose. The interval between the two medial bands corresponds with the depression, called the philtrum, seen on the lip beneath the septum of the nose. The additional fibers for the lower lip constitute a slip m. incisivus labii inferioris on either side of the middle line; this arises from the mandible, lateral to the Mentalis, and intermingles with the other muscles at the angle of the mouth. Clinical significance Babies are occasionally born without one or both sides of this particular muscle, resulting in a slight droop to the affected side of the face. Additional images See also Snout reflex References External links Facial Muscles - BBC Picture of the circular-shaped muscle Facial Muscles - BBC (Flash) Animation of movements of the muscle Muscles of the head and neck