Post-Traumatic Trigeminal Neuropathy Caused by an Orbital Stab Wound

Sensory and motor neuropathy of the trigeminal nerve due to trauma is quite rare. Furthermore, there have been no detailed reports on occlusal abnormalities and trismus associated with post-traumatic trigeminal motor neuropathy. Here, the authors report a case of trigeminal motor neuropathy and trigeminal sensory neuropathy in all 3 divisions caused by an orbital stab wound. During kendo practice, a 61-year-old man was injured in his right medial canthus with the splinter of a broken bamboo sword. Imaging examinations did not show a brain injury or orbital bone fracture. Intraoral and extraoral examination and needle electromyography revealed trismus, posterior open bite, and denervation of the right masseter. After the injury, the patient strived to use the right molars during mastication and began chewing exercises in the right molar region. A follow-up examination 7 months after the injury revealed an improvement of the functional problems in the masticatory system. Although slight facial numbness in the right ophthalmic division remained, the patient was satisfied with the present status. Further knowledge concerning the natural history of trigeminal neuropathy as well as the treatment of choice should be explored in the future.