The (A) frontal and (B) lateral surface views of the skull indicate the osteotomy lines for a level III transbasal approach. (C) The extended orbital bar osteotomy is shown as resected in a bilateral osteotomy. Again, the extent of a level III transbasal approach can be tailored to the pathology. By definition, one medial and one lateral canthus on the same side are taken down with the osteotomy to incorporate at least one infraorbital fissure located on the side of medial canthus detachment. (Reprinted with permission from Feiz-Erfan I, Han PP, Spetzler RF, et al. The radical transbasal approach for resection of anterior and midline skull base lesions. J Neurosurg 2005;103:485–490.)