Endoscopic picture of the anterior and inferior surfaces of the sphenoid bone.
The anterior surface of the sphenoid bone presents in the midlaine, a vertical ridge of bone, the ethmoidal crest (also known as the sphenoidal crest), which articulates with the perpendicular plate of the ethmoid, forming part of the septum of the nose.
The inferior surface presents in the midline, a triangular spine, the rostrum (also known as the "keel"), which is continuous with the ethmoidal crest on the anterior surface and articulates with the alae of the vomer.
Endoscopic picture of an opened sphenoid sinus showing the floor of the sella turcica.
The ethmoidal crest (sphenoidal crest) has been removed to gain access to the right sphenoid sinus.
The Intersphenoid septum is seen near the right margin of the opening. It is very common to find the intersphenoid septum to one side of the midline or the other, thus accounting for the tremendous asymmetry of the paired sphenoid sinuses.
In the midline of the roof of the sphenoid sinus, there is a round elevation that corresponds to the floor of the sella turcica. The bone that separates the sinus from the pituitary fossa is very thin and sometimes inexistent in the presence of a pituitary macroadenoma.