Supratrochlear Nerve

Description

Emerging from the ophthalmic division of the trigeminal nerve (V1) via the frontal nerve, the supratrochlear nerve courses anteriorly within the orbit and approaches the superior orbital rim near the medial canthus. It passes superior to the trochlea of the superior oblique muscle, then ascends in the forehead within the superficial fascia, typically medial to the supraorbital nerve. Bony landmarks such as the frontal bone, orbital margins, nasal bones, and maxilla frame its path, with the nasal cavity and dental arcade providing orientation in the anterior skull base. Clinical relevance centers on sensory territory and predictable entrapment points. The supratrochlear nerve supplies cutaneous sensation over the glabella and medial forehead, and irritation or injury near the superior orbital margin can contribute to frontal neuralgia or post-traumatic dysesthesia after brow lacerations. Its close relationship to the trochlea and medial orbital rim also matters during upper eyelid surgery and endoscopic brow lift, where traction or cautery can denervate the medial forehead, and during targeted nerve blocks used for forehead laceration repair or migraine-related pain syndromes. Small structure, real consequences. Educators can pair this figure with a head and neck module on cranial nerve branches, using it to contrast supratrochlear versus supraorbital distributions and to reinforce V1 sensory mapping in the context of the orbit and frontal bone. It also fits well in surgical anatomy references for periocular approaches, regional anesthesia guides for supratrochlear nerve block technique, and neurology teaching files discussing trigeminal distribution patterns in facial pain. Anatomical accuracy verified by SciePro's Medical Advisory Board.