Frontal nerve

The frontal nerve is the largest branch of the ophthalmic, and may be regarded, both from its size and direction, as the continuation of the nerve.

It enters the orbit through the superior orbital fissure, and runs forward between the Levator palpebræ superioris and the periosteum.

Midway between the apex and base of the orbit it divides into two branches, supratrochlear nerve and supraorbital nerve.

Functions
It provides the sensory innervations for the skin of the forehead, mucosa of frontal sinus, and the skin of the upper eyelid.