Here, the extent of orbital osteotomies for a level I transbasal approach varies depending on the surgical need. (A) The entire orbital rim and nasion are included. (B) The osteotomy line is indicated as a dashed line traversing the frontal fossa. (Reprinted from Lawton MT, Beals SP, Joganic EF, Han PP, Spetzler RF. The transfacial approaches to midline skull base lesions: a classification scheme. Operative Techniques in Neurosurgery 1999;2:1–18, with permission from Elsevier.)