Limited zygomatic osteotomy for skull base lesions: A cadaveric study

Zygomatic osteotomy has been advocated for the treatment of difficult skull base lesions. To study the relative increase in exposure gained by removing portions of the zygoma, we have performed dissections on five fresh-frozen and lightly-perfused cadavers (10 sides, total). Angles of approach to the basilar apex, posterior clinoid, and troclear nerve were quantified with the aid of a Stealth Station frameless stereotactic system, with which we were able to record instrument position at the circumferential limits of exposure. Most of the additional exposure gained in the removal of the zygoma is due to removal of the orbital rim and frontozygomatic process, while less additional exposure is gained in removal of the entire zygomatic arch. Based upon these dissections, as well as our operative experience, we have concluded that osteotomy of the entire zygoma is rarely necessary. Only the most extensive skull base lesions and those involving the infratemporal fossa are likely to require osteotomy of the complete zygoma.