Surgical implications of an unusual anomaly of the infraorbital nerve.

The infraorbital nerve is a direct extension of the maxillary division of the Vth cranial nerve. It typically courses anteriorly through a canal within the bone of the orbital floor. We describe an unusual anatomic variation of this canal that to our knowledge has not been previously described in the literature. This anomaly may have significant implications during surgery on the paranasal sinuses and maxillofacial skeleton. Careful preoperative assessment of the course of the infraorbital nerve is necessary to prevent iatrogenic hypoesthesia, paresthesia, or neuralgia.