Infraorbital nerve


The infraorbital nerve is a branch of the maxillary nerve, itself a branch of the trigeminal nerve. It travels through the orbit and enters the infraorbital canal to exit onto the face through the infraorbital foramen. It provides sensory innervation to the skin and mucous membranes around the middle of the face.

Structure

The infraorbital nerve travels with the infraorbital artery and vein. It branches from the maxillary nerve in the pterygopalatine fossa and travels through the inferior orbital fissure to enter the orbit. It runs anteriorly along the floor of the orbit in the infraorbital groove to the infraorbital canal of the maxilla. Within the infraorbital canal it has three branches, the posterior superior alveolar nerve, middle superior alveolar nerve and anterior superior alveolar nerve. After traversing the canal it emerges onto the anterior surface of the maxilla through the infraorbital foramen. Here, it divides into its terminal branches; palpebral, nasal and superior labial.

Branches

Within infraorbital canal from proximal to distal:
After it exits the infraorbital foramen:
The palpebral branches ascend deep to the orbicularis oculi and pierce the muscle to supply the skin of the lower eyelid. The nasal branches supply the skin of the side of the nose and the moveable part of the nasal septum. The superior labial branches descend deep to the levator labii superioris to supply the skin of the anterior cheek and upper lip.

Function

The infraorbital nerve provides sensory innervation to the skin of the lower eyelid, side of the nose, moveable part of nasal septum, anterior cheek and upper lip. It does not provide motor innervation to any muscles.

Clinical significance

Infraorbital nerve block

The infraorbital nerve is often transiently blocked with local anesthetic to induce analgesia during dental or surgical procedures of the face.

Trigeminal neuralgia

The infraorbital nerve can be implicated in trigeminal neuralgia, where patients have severe facial pain.

Orbital fracture

A fracture of the floor of the orbit can injure the infraorbital nerve resulting in anesthesia in its sensory distribution.