sphenoid sinus
sphenoidal sinus

Deep pain behind the eyes or headache in the back of the head may mean an infection in the sphenoidal sinuses.

There is also evidence to show that the sphenoidal sinus may extend into the occipital bone after the age of twenty-five (Dutra, 1944).

It lies posterior and superior to the superior concha into which the sphenoidal sinus opens.

Surgical drainage with sphenoidotomy is indicated if the primary site of infection is thought to be the sphenoidal sinuses.

The sphenoidal sinuses are present as minute cavities at the time of birth (Onodi), but do not attain their full size until after puberty.

An aperture of variable size exists in the anterior wall of each, and through this the sphenoidal sinus opens into the nasal cavity.

More rarely it opens on both surfaces, and then communicates with the posterior ethmoidal cells and the sphenoidal sinus.

Access to the sphenoidal sinus can either be transnasal (through the nostril) or sublabial (through an incision under the top lip).

The posterior group (sometimes the posterior ethmoid sinus) drains into the superior meatus above the middle nasal concha; sometimes one or more opens into the sphenoidal sinus.

"The doctors," he continued, "needed to repair damage to the left frontal sinus, the sphenoidal sinus, and the sinus cavernous, which had all been partially crushed by that pewter candlestick.

The two sphenoidal sinuses (or sphenoid) contained within the body of the sphenoid vary in size and shape; owing to the lateral displacement of the intervening septum they are rarely symmetrical.

The ethmoidal nerves, which arise from the nasociliary nerve, supply the ethmoidal cells; the posterior branch leaves the orbital cavity through the posterior ethmoidal foramen and gives some filaments to the sphenoidal sinus.

Transsphenoidal surgery (removal of the tumor by an operation through the nose and the sphenoidal sinuses) may, apart from addressing symptoms related to the tumor, also improve pituitary function, although the gland is sometimes damaged further as a result of the surgery.

Here it gives off its posterior lateral nasal branches which spread forward over the conchæ and meatuses, anastomose with the ethmoidal arteries and the nasal branches of the descending palatine, and assist in supplying the frontal, maxillary, ethmoidal, and sphenoidal sinuses.