any structural anomaly of the oval-shaped opening in the middle cranial fossa located at the posterior base of the greater wing of the sphenoid bone, lateral to the lingual; it transmits the mandibular division of the trigeminal nerve, accessory meningeal artery, emissary veins between the cavernous sinuses and pterygoid plexus, otic ganglion, and occasionally the nervus spinosus and lesser petrosal nerve