sphenoid sinus

Last reviewed 01/2018

The sphenoid sinus lies deep in the middle of the skull. It drains anteriorly into the sphenoethmoidal recess, which lies above the superior turbinate.

The sphenoid sinus is flanked by the cavernous sinuses and so is closely related to the internal carotid arteries and cranial nerves III-VI. These relations are important in transphenoidal surgery. The optic foramen, containing the optic nerve, is closely apposed to the sphenoid at the outer anterior angle where the roof and lateral wall meet.