The trigeminal nerve. Part II: the ophthalmic division

The ophthalmic, or first division (V1) of the trigeminal nerve, is the smallest of the three divisions and is purely sensory or afferent in function. It supplies sensory branches to the ciliary body, the cornea, and the iris; to the lacrimal gland and conjunctiva; to portions of the mucous membrane of the nasal cavity, sphenoidal sinus, and frontal sinus; to the skin of the eyebrow, eyelids, forehead, and nose; and to the tentorium cerebelli, dura mater, and the posterior area of the falx cerebri. At first glance, one might not expect one interested in the diagnosis and treatment of orofacial pain and temporomandibular joint disorders to have a need to be concerned with the ophthalmic division. Although much of this division's influence is dedicated to structures within the orbit, nose, and cranium, still, the ophthalmic division may be afflicted with a lesion or structural disorder which can cause all sorts of orofacial pain. Ignorance of this or any portion of the trigeminal nerve will lead to diagnostic and therapeutic failures. In this, the second of four (4) articles concerning the trigeminal nerve, the first division of this vast cranial nerve will be described in detail.