General Medical Information

Sphenoid Sinus

Susan D. John
Michael D. Maves

The sphenoid sinus usually opens into the sphenoethmoidal recess above and behind the superior nasal concha. The ostium usually is in the posterior wall of the recess, but sometimes it is on its lateral wall. The degree of pneumatization of the sphenoid sinus varies. This variation is an important factor in surgical approaches to the pituitary gland. The relations of the sphenoid sinus are important because of the surrounding anatomic structures. The optic nerves are superior to the sinus, and the internal carotid artery is lateral to the sinus within the cavernous sinus. The maxillary nerve lies in the inferior lateral portion of the sinus in the anterior aspect. The hypophysis lies within the posterior superior portion of the sphenoid sinus and can be approached through transsphenoidal hypophysectomy.