Nerve · Jaw

Mental nerve

Nervus mentalis

The nerve of the chin and lower lip, and one of the two end-branches of the inferior alveolar nerve. It leaves the jawbone through the mental foramen — a small opening on the outer surface of the mandible below the premolars — and divides at once beneath depressor anguli oris into branches for the skin of the chin and for the skin, mucous membrane and gum of the lower lip. Its name comes from the Latin *mentum*, chin, and has nothing to do with the mind. The position of the foramen it emerges from is not fixed for life: as the tooth-bearing part of the jaw resorbs after teeth are lost, the foramen comes to lie closer to the upper border of the bone.