Inferior alveolar nerve

Last revised by Assoc Prof Craig Hacking on 20 Sep 2020

The inferior alveolar nerve or inferior dental nerve is a mixed sensory and motor branch of the posterior division of the mandibular division of the trigeminal nerve, located in the pteryogomandibular space of the oral cavity/masticator space.

Gross anatomy

The inferior alveolar nerve divides off the posterior division and descends posterior to the lingual nerve, deep to lateral pterygoid muscle and lateral to the pterygomandibular raphe, between the sphenomandibular ligament and the ramus of the mandible. It enters the mandibular foramen anterior to the inferior alveolar artery and vein. It then courses in the mandibular canal.

The inferior alveolar nerve has three major branches:

  • nerve to mylohyoid, which takes off just before entering the mandible (supplying the mylohyoid and anterior belly of digastric muscle). 
  • incisive nerve, which is a terminal branch (supplying the pulps and periodontal membranes of the canine and both incisors)
  • mental nerve, which is a terminal branch (supplying the skin and mucous membrane of the lower lip and labial gum from the mid-line to second premolar tooth). 

In the mandibular canal, the nerve also gives off small unnamed twigs that contribute to contributes to the inferior dental plexus (supplying the mandibular three molar and two premolar teeth).

Variant anatomy

Some authors document the mental nerve carrying parasympathetic fibers from the otic ganglion to the labial glands of the lower lip.

Anatomy: Head and neck

Anatomy: Head and neck

ADVERTISEMENT: Supporters see fewer/no ads

Cases and figures

  • Figure 1
    Drag here to reorder.
  • Figure 2: maxillary and mandibular divisions of the trigeminal nerve (Gray's illustration)
    Drag here to reorder.
  • Figure 3: mandibular division of the trigeminal nerve (Gray's illustration)
    Drag here to reorder.
  • Figure 4: mandibular division of the trigeminal nerve and submandibular and otic ganglia (Gray's illustration)
    Drag here to reorder.
  • Updating… Please wait.

     Unable to process the form. Check for errors and try again.

     Thank you for updating your details.