Frontal nerve
The frontal nerve is the largest branch of the ophthalmic nerve, itself a branch of the trigeminal nerve.Structure
The frontal nerve branches from the ophthalmic nerve immediately before entering the superior orbital fissure. In then travels superolateral to the annulus of Zinn between the lacrimal nerve and inferior ophthalmic vein. After entering the orbit it travels anteriorly between the roof periosteum and the levator palpebrae superioris. Midway between the apex and base of the orbit it divides into two branches, the supratrochlear nerve and supraorbital nerve.Functions
The two branches of the frontal nerve provide sensory innervation to the skin of the forehead, mucosa of the frontal sinus, and the skin of the upper eyelid.
