Three-Piece Orbitozygomatic Craniotomy. A, Inset shows the site of the skin incision. The first osteotomy divides the anterior and posterior end of the zygomatic arch so that the arch and temporalis muscle can be folded downward to increase the exposure of the middle fossa. The second bone cut is around the pterional bone flap, which has been completed, and the third cut is the orbitozygomatic osteotomy. B, The dura has been elevated from the roof and lateral wall of the orbit and the sphenoid ridge has been removed. The third piece, the orbitozygomatic osteotomy, includes the roof and the portion of the lateral wall of the orbit as outlined. C, The floor of the middle fossa has been removed to expose the mandibular nerve, lateral pterygoid muscle, and terminal part of the maxillary artery in the infratemporal fossa. The bone lateral to the trigeminal nerve has been removed to expose the horizontal segment. D, The cervical carotid and the branches of the mandibular nerve have been exposed in the infratemporal area. The eustachian tube and tensor tympani muscle are layered along the anterior margin of the horizontal segment. E, The tensor tympani and eustachian tube have been resected to expose the posterior genu and posterior vertical and horizontal segments. F, The petrous carotid has been reflected forward to expose the petrous apex and clivus on the medial side of the carotid canal. G, The petrous apex and lateral part of the clivus have been removed and the dura opened to expose the pons, medulla, anterior and posterior inferior cerebellar and vertebral arteries, and hypoglossal nerve. The opening through the petrous apex and clivus is located anterior to where cranial nerves IX to XII exit the jugular foramen. (Images courtesy of AL Rhoton, Jr.)