The foramen ovale is an oval opening in the greater wing of the sphenoid bone at the base of the skull, transmitting the mandibular nerve (V3) from the middle cranial fossa into the infratemporal fossa, the accessory meningeal artery, and the lesser petrosal nerve. It is located posteromedial to the foramen spinosum and anterolateral to the foramen lacerum in the skull base.
The foramen ovale is the target for percutaneous procedures aimed at the trigeminal ganglion for trigeminal neuralgia treatment: percutaneous radiofrequency rhizotomy, glycerol injection, and balloon compression all access the Gasserian ganglion by needle passage through the foramen ovale under fluoroscopic guidance with the cheek entry point. CT-guided biopsy of the skull base at the foramen ovale level is performed for perineural tumour spread evaluation from head and neck cancers that track along V3.
Needle passage through the foramen ovale under fluoroscopic guidance provides access to the trigeminal ganglion for percutaneous radiofrequency ablation, glycerol injection, or balloon compression of the trigeminal root for drug-refractory trigeminal neuralgia, with careful patient positioning using the cheek puncture landmark to align the needle trajectory.
Nasopharyngeal, parotid, and skin cancers spread perineurally along V3 branches back through the foramen ovale to the trigeminal ganglion and cavernous sinus, producing facial numbness and jaw weakness that may be the presenting sign of occult malignancy; MRI with fat suppression demonstrates neural thickening at the foramen.
