infraorbital

Infraorbital refers to structures located in or passing beneath the orbit, the bony cavity that houses the eye. In anatomy, the term is most often used to describe the infraorbital nerve and artery, as well as the infraorbital foramen and canal, which together form a key pathway for midface innervation and blood supply.

The infraorbital canal begins at the infraorbital groove on the floor of the orbit and runs within the maxilla to the infraorbital foramen on the face, typically about one centimeter below the lower orbital rim. The infraorbital nerve is a sensory branch of the maxillary division (V2) of the trigeminal nerve. It enters the infraorbital canal, gives off nasal and oral branches within the canal, and exits at the infraorbital foramen to supply sensation to the lower eyelid, lateral aspect of the nose, upper lip, and cheek. The accompanying infraorbital artery arises from the maxillary artery and travels with the nerve, providing vascular supply to the midface.

Clinically, the infraorbital region is important in regional anesthesia, with infraorbital nerve blocks used to anesthetize the midface for dental, maxillofacial, or ophthalmic procedures. Infraorbital fractures involve the orbital floor or infraorbital rim and can injure the nerve, leading to facial numbness. Radiographic imaging, including CT, can visualize the canal and foramen for diagnosis or surgical planning.