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 supraorbital foramen, 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. [WP,unvetted]. [ http://en.wikipedia.org/wiki/Frontal_nerve ]