Mental nerve is a sensory nerve which provides sensation to the front of the chin and lower lip as well as the labial gingivae of the mandibular anterior teeth and the premolars. It is a branch of the posterior trunk of the inferior alveolar nerve, which is itself a branch of the mandibular division of the trigeminal nerve (CN V). Mental nerve is a sensory nerve which provides sensation to the front of the chin and lower lip as well as the labial gingivae of the mandibular anterior teeth and the premolars. It is a branch of the posterior trunk of the inferior alveolar nerve, which is itself a branch of the mandibular division of the trigeminal nerve (CN V). The nerve emerges at the mental foramen in the mandible, and divides beneath the Depressor anguli oris muscle into three branches: These branches communicate freely with the facial nerve. The mental nerve can be blocked with local anesthesia, a procedure used in surgery of the chin, lower lip and buccal mucosa from midline to the second premolar. In this technique, local anesthetic is infiltrated in the soft tissue surrounding the mental foramen. This article incorporates text in the public domain from page 897 of the 20th edition of Gray's Anatomy (1918)