The supraorbital and [[supratrochlear nerve]]s arise from the [[frontal nerve]] and are 2 of the 5 branches of [[V1]] (ophthalmic division of the [[trigeminal nerve]]). The supraorbital [[nerve]] is the largest branch. It exits the [[orbit]] through the [[supraorbital notch]] or foramen, usually within the medial third of the orbital roof (mean distance from exit to medial angle of the orbit: 20 mm (range: 5–47)
((Andersen NB, Bovim G, Sjaastad O. The frontotemporal peripheral nerves. Topographic variations of
the supraorbital, supratrochlear and auriculotemporal nerves and their possible clinical significance.
Surgical and Radiologic Anatomy. 2001; 23:97–104))).
The [[supratrochlear nerve]] exits the orbit without a foramen or notch 3–38 mm medial to the supraorbital nerve (mean: 15.3 mm
((Andersen NB, Bovim G, Sjaastad O. The frontotemporal peripheral nerves. Topographic variations of
the supraorbital, supratrochlear and auriculotemporal nerves and their possible clinical significance.
Surgical and Radiologic Anatomy. 2001; 23:97–104)));
the most medial branch varies from 8–30 mm lateral to the patient’s
midline
((Andersen NB, Bovim G, Sjaastad O. The frontotemporal peripheral nerves. Topographic variations of
the supraorbital, supratrochlear and auriculotemporal nerves and their possible clinical significance.
Surgical and Radiologic Anatomy. 2001; 23:97–104)))

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It is smaller than the nearby supraorbital nerve. It passes above the pulley of the Superior oblique muscle and gives off a descending filament that joins the infratrochlear branch of the nasociliary nerve.

The supratrochlear nerve then exits the orbit between the pulley of the superior oblique and the supraorbital foramen, curves up on to the forehead close to the bone, and ascends beneath the Corrugator supercilii and Frontalis muscles. It then divides into branches which pierce these muscles and supplies the following areas:

skin of the lower part of the forehead, close to the midline
conjunctiva
skin of the upper eyelid.