Mental nerve is a general somatic afferent (sensory) nerve which provides sensation to the anterior aspects of the chin and lower lip as well as the buccal gingivae of the mandibular anterior teeth and the premolars. It is a branch of the posterior trunk of the inferior alveolar nerve

Inferior alveolar nerve

The inferior alveolar nerve is a branch of the mandibular nerve, which is itself the third branch of the trigeminal nerve .-Path:...

, which is itself a branch of the mandibular division of the trigeminal nerve

Trigeminal nerve

The trigeminal nerve contains both sensory and motor fibres. It is responsible for sensation in the face and certain motor functions such as biting, chewing, and swallowing. Sensory information from the face and body is processed by parallel pathways in the central nervous system...

 (CN V).

The nerve emerges at the mental foramen

Mental foramen

The mental foramen is one of two holes located on the anterior surface of the mandible. It permits passage of the mental nerve and vessels. The mental foramen descends slightly in edentulous individuals.- Variations :...

 in the mandibula, and divides beneath the Depressor anguli oris muscle

Depressor anguli oris muscle

The Depressor anguli oris arises from the oblique line of the mandible, whence its fibres converge, to be inserted, by a narrow fasciculus, into the angle of the mouth.-Anatomy:...

 into three branches:

• one descends to the skin of the chin
  Chin
  In the human anatomy, the chin is the lowermost part of the face.It is formed by the lower front of the mandible.People show a wide variety of chin structures. See Cleft chin....
  
  .
• two ascend to the skin and mucous membrane of the lower lip
  Lower lip
  The lower lip covers the anterior body of the mandible.It is lowered by the Depressor labii inferioris muscle....
  
  .

These branches communicate freely with the facial nerve

Facial nerve

The facial nerve is the seventh of twelve paired cranial nerves. It emerges from the brainstem between the pons and the medulla, and controls the muscles of facial expression, and functions in the conveyance of taste sensations from the anterior two-thirds of the tongue and oral cavity...

.

Anesthesia

The mental nerve can be blocked with local anesthesia

Local anesthesia

Local anesthesia is any technique to induce the absence of sensation in part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. It allows patients to undergo surgical and dental procedures with...

, 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.

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