Preservation of the Integrity of the Infraorbital Nerve in Facial Translocation

The infraorbital nerve represents the largest cutaneous branch of the maxillary nerve to supply the area of skin derived from the embryonic maxillary prominence. It emerges from the infraorbital foramen on a line that runs almost vertically through the pupil to supply sensation to the cutaneous surfaces of the lateral aspect of the nose, upper lip, and lower eyelid. It is important to positively identify this nerve and preserve it, whenever possible, during all midfacial osseous procedures. This nerve is quite sensitive to traction injuries, often leaving patients with prolonged hypoesthesia and dysesthesia. During the past two decades skull base surgeons have greatly expanded the resectability of a number of lesions of the skull base, chiefly as a result of improved exposure, allowing for safer and more complete removal. Modular disassembly of the facial skeleton along esthetic facial subunits is the basis of facial translocation or disassembly approaches. Improvement in accessibility at the level of the skull base is often coupled to diminished function of less vital neural elements anteriorly. In extensive facial translocation approaches to the skull base, a number of surgeons have espoused elective transection of the infraorbital nerve (and occasionally the frontal branch of the seventh cranial nerve) with anastomosis at the completion of the procedure. This was performed in an effort to avoid the troublesome dysesthesias associated with the prolonged nerve traction often required during resection and reconstruction of skull base tumors and defects. In fact, simple midfacial degloving is associated with alterations in sensation over the distribution of the infraorbital nerve in nearly all patients undergoing the procedure. Hypoesthesia, once present, often lasts for 3 to 6 months after surgery and may, rarely, be permanent. This brief article outlines my approach to routinely preserving the function of the infraorbital nerve (without any significant postoperative sensory deficit) while improving access for facial translocation procedures.