Which CN V1 branch supplies sensation to the forehead and scalp?

• A. Supraorbital nerve
• B. Infratrochlear nerve
• C. Nasociliary nerve
• D. Lacrimal nerve

Answer: (A)

The forehead and anterior scalp receive sensation mainly from the supraorbital nerve, a branch of the frontal nerve which is part of CN V1. The frontal nerve splits into supraorbital and supratrochlear branches; the supraorbital nerve exits the orbit through the supraorbital foramen/notch and supplies most of the forehead and frontal scalp. The other nerves listed have more limited or different territories: infratrochlear supplies the medial canthus and part of the upper eyelid, nasociliary carries sensation from the eyeball region and nose, and lacrimal supplies the lacrimal gland and lateral upper eyelid. Thus, the branch that covers the forehead and scalp is the supraorbital nerve.