Lesser Wing Of The Sphenoid, Posterior View

Description

Lesser wing (ala minor) of the sphenoid is presented from a posterior, endocranial perspective, emphasizing the thin, sharp bony plates that project laterally from the sphenoid body and terminate medially as the anterior clinoid process. Medial to lateral, the lesser wing forms part of the floor of the anterior cranial fossa, with its posterior margin defining the sphenoidal ridge that separates frontal lobe impressions superiorly from the middle cranial fossa inferiorly. Near the root of the wing, the optic canal is evident at the junction of the sphenoid body and lesser wing, positioned medial to the superior orbital fissure region and superior to the greater wing. Edges matter here. This is the surface and set of landmarks surgeons reference when discussing optic nerve decompression and anterior clinoidectomy, because the anterior clinoid process and optic canal lie in close proximity to the internal carotid artery and cavernous sinus contents just inferomedial to the lesser wing. Hyperostosis or meningioma along the sphenoid ridge can narrow the optic canal and produce compressive optic neuropathy, and trauma to the skull base can propagate fracture lines through these thin plates with associated orbital apex complications. A posterior view is also the most direct way to teach how the lesser wing contributes to the anterior cranial base while simultaneously forming the superior boundary of the orbit, without the distraction of facial bones. Use this illustration in skull and cranium anatomy labs, neurosurgical or ENT teaching on the orbital apex and parasellar region, and in atlas plates or journal figures discussing sphenoid bone variants, fractures, or sphenoid ridge meningioma relationships. Anatomical accuracy verified by SciePro's Medical Advisory Board.