<aside>

The sphenoid is a complex, unpaired midline bone of the skull base, often called the “keystone of the cranial floor” because it articulates with nearly all other cranial bones. It contributes to the anterior and middle cranial fossae, orbits, nasal cavity, and skull base foramina.

</aside>

![The anatomy of the greater wings of the sphenoid bone (GWS). Illustrations show the anterior (1A, 1B), posterior (2A, 2B), superior (3A, 3B), and inferior (4A, 4B) views of the sphenoid bone, with the GWS in oil blue.

Cochinski R, Agarwal M, Albuquerque J, et al. Anatomy and Diseases of the Greater Wings of the Sphenoid Bone. RadioGraphics. 2022;42(4):1177-1195. doi:https://doi.org/10.1148/rg.210094](attachment:f72332e1-2682-4dc7-9242-d1ee69f7acc8:image.png)

The anatomy of the greater wings of the sphenoid bone (GWS). Illustrations show the anterior (1A, 1B), posterior (2A, 2B), superior (3A, 3B), and inferior (4A, 4B) views of the sphenoid bone, with the GWS in oil blue.

Cochinski R, Agarwal M, Albuquerque J, et al. Anatomy and Diseases of the Greater Wings of the Sphenoid Bone. RadioGraphics. 2022;42(4):1177-1195. doi:https://doi.org/10.1148/rg.210094

Embryology

• Develops by endochondral ossification from cartilaginous precursors.
• Ossification centers: presphenoid, postsphenoid, and alisphenoids (greater wings).
• Fusion complete by late adolescence.

Anatomy

Parts of sphenoid bone

Important Relations

• Superiorly: frontal lobe, pituitary gland (in sella).
• Laterally: temporal lobe, cavernous sinus, middle cranial fossa.
• Inferiorly: nasopharynx.
• Anteriorly: ethmoid and nasal cavity.

Foramina and Structures Transmitted

• Optic canal – optic nerve, ophthalmic artery.