The infra-orbital nerve is a branches of the maxillary division of the trigeminal nerve.
The infra-orbital nerve divides off the maxillary division just after emerging from the foramen rotundum to enter the pterygopalatine fossa. It courses laterally over the palatine bone and maxilla to enter the orbit through the inferior orbital fissure. It then runs anteriorly in the inferior aspect of the extraconal space within the infra-orbital groove. Within the groove, it gives of sensory branches to the maxillary teeth:
- palpebral branches to the lower eyelid and cheek
- nasal branches to the side and ala of nose
- join the external nasal branch of the anterior ethmoidal nerve
- superior labial branches to the upper lip and labial gum
- join branches of the facial nerve to form the infraorbital plexus
The nerve is a risk of injury with orbital blowout fractures.
This nerve is also commonly implicated in trigeminal neuralgia which is amenable to cryotherapy when refractory to medical therapy.