Structure and Function - The mental nerve is a branch of the posterior trunk of the inferior alveolar nerve. - It emerges from the mental foramen in the mandible. - It divides into three branches beneath the depressor anguli oris muscle. - One branch descends to the skin of the chin. - Two branches ascend to the skin and mucous membrane of the lower lip. - The mental nerve provides sensation to the front of the chin and the lower lip. - It also provides sensation to some of the gums of the anterior mandibular (lower) teeth.

Clinical significance of the mental nerve - The mental nerve can be blocked with local anaesthesia for surgery of the chin, lower lip, and buccal mucosa. - Local anesthetic is injected into the soft tissue surrounding the mental foramen. - Problems with the mental nerve can cause numbness over the chin. - Chin numbness can be caused by various illnesses.

Anaesthesia - The mental nerve can be blocked with local anaesthesia. - This can be used in surgery of the chin, lower lip, and buccal mucosa. - In animals, it can be used in surgery of the lower lip and lower teeth anterior to the site of administration. - Local anesthetic is injected into the soft tissue surrounding the mental foramen. - Injection into the mental foramen itself can cause damage.

Chin numbness - Problems with the mental nerve can cause numbness over the chin. - Chin numbness can be caused by various illnesses.

Reflexes - Stimulation of the mental nerve with electricity inhibits muscles that close the jaw. - This is a brainstem reflex.