Variations in emergence and course of the inferior palpebral nerve.

Comprehensive understanding of the anatomy of the inferior palpebral (IP) nerve is crucial to preservation of sensation in the inferior eyelid and conjunctiva. Iatrogenic injuries may occur during blepharoplasty, repair of orbitozygomatic fracture and other maxillofacial surgeries involving this region. Although several studies depict the anatomical variations of the main infraorbital nerve (ION), little information exclusive to the IP nerve exists. This study provides information on the additional variations of the ION with reference to the IP nerve. The study was performed on 84 IP nerves by dissection of 42 formalin-fixed cadavers from the laboratory of topographic anatomy, Department of Human Anatomy, University of Nairobi, Kenya. Each of the nerves were exposed at the emergence and followed to their termination. Variations encountered involved emergence, course, and even absence. Variant emergence was through an accessory infraorbital foramen, an infraorbital notch, and as a common trunk with the external nasal nerve. This nerve shows high anatomical variability that may account for the difficulties and complications encountered in clinical interventions. It is believed that this information will improve clinical management of conditions affecting the region of distribution of the IP nerve.