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 anesthesia 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 anesthesia.
- 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.