Lesser Wing Of The Sphenoid, Lateral View

Description

Lesser wing (ala minor) of the sphenoid projects laterally from the sphenoid body as a thin, sharp plate forming the posterior margin of the anterior cranial fossa and the posterior roof of the orbit. In this lateral perspective, the sphenoidal ridge is emphasized, with the greater wing positioned inferior and posterior to it, explaining why the ala minor is often partly concealed by the broader ala major. Medially, the root of the lesser wing abuts the region of the optic canal, and its medial end rises toward the anterior clinoid process, a bony prominence that overhangs the parasellar compartment. Edges matter here. Skull base surgeons and neuroradiologists care about this contour because the lesser wing defines key corridors around the optic nerve and internal carotid artery, and it provides a common attachment line for dura that can harbor sphenoid wing and parasellar meningiomas. Anterior clinoid hypertrophy or hyperostosis from meningioma can narrow the optic canal and contribute to progressive visual loss, and fractures traversing the sphenoid ridge may extend toward the superior orbital fissure with ophthalmoplegia or trigeminal sensory deficits. The fixed lateral view makes the overlap between lesser and greater wings easy to read, which helps when teaching why the optic strut and anterior clinoid are approached from a lateral skull base exposure. Use this illustration in gross anatomy and neuroanatomy courses to anchor the boundaries of the anterior cranial fossa and orbit, and in operative atlases when describing extradural anterior clinoidectomy, optic canal unroofing, or sphenoid wing drilling. It also pairs well with CT bone window teaching files, where the ala minor appears as a thin shelf above the superior orbital fissure and lateral to the planum sphenoidale. Anatomical accuracy verified by SciePro's Medical Advisory Board.