Structure and Variation - The zygomatic nerve is a branch of the maxillary nerve (CN V) that arises at the pterygopalatine ganglion. - It exits from the pterygopalatine fossa through the inferior orbital fissure to enter the orbit. - In the orbit, it travels anteriorly along its lateral wall. - It divides into branches: zygomaticotemporal nerve, zygomaticofacial nerve, and a communicating branch to the lacrimal nerve. - Variation: Sometimes, the zygomatic nerve does not branch within the orbit. Instead, it enters a single foramen in the zygomatic bone called the zygomatico-orbital foramen. In this case, it divides within the bone into the zygomaticotemporal nerve and the zygomaticofacial nerve.

Function - The terminal branches of the zygomatic nerve contain sensory axons, providing sensation to the skin over the temporal bone and the zygomatic bone. - The zygomatic nerve also carries postganglionic parasympathetic axons from the pterygopalatine ganglion. - These axons travel from the ganglion to the zygomatic nerve and then to the lacrimal nerve through a communicating branch, providing secretomotor supply to the lacrimal gland.

Clinical Significance - The zygomatic nerve can be blocked indirectly by anesthetizing the maxillary nerve (CN V). - Fractures to the zygomatic bone can damage the zygomatic nerve and its branches.

Additional Images - The nerves of the scalp, face, and side of the neck. - Branches of the trigeminal nerve. The zygomatic nerve is visible branching from the maxillary nerve and entering the orbit.

Summary - The zygomatic nerve is a branch of the maxillary nerve that travels through the pterygopalatine fossa and inferior orbital fissure to enter the orbit. - It divides into branches within the orbit and provides sensory innervation to the temporal and zygomatic bones. - It also carries parasympathetic axons to the lacrimal gland. - Clinical significance includes indirect blockage through the maxillary nerve and potential damage from zygomatic bone fractures.