[1] The frontal nerve branches 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.

The two branches of the frontal nerve provide sensory innervation to the skin of the forehead, mucosa of the frontal sinus (an air sinus), and the skin of the upper eyelid.

[2] A CT scan or magnetic resonance imaging may be used to identify the extent of the cancer.