Trigeminal nerve injuries in oral and maxillofacial surgery: a literature review

Objective: Trigeminal nerve injury is an uncommon complication of outpatient oral surgery and dental procedures such as removal of impacted teeth, placement of endosseous dental implants, and even injection of local anesthesia. In the field of oral and maxillofacial surgery, the two most commonly injured branches of the trigeminal nerve are the inferior alveolar and lingual nerves. Fortunately, most nerve injuries will undergo spontaneous recovery, with only a small percentage of cases resulting in permanent sensory deficits. Background: There is significant morbidity associated with trigeminal nerve injuries, however. Affected patients may complain of difficulty with speech, mastication, and dysesthesia among other symptoms. Once a nerve injury has been identified, the degree of injury is defined based on published classification systems such as the Medical Research Council Scale. Specific neurosensory testing can be performed in the office, and serial neurosensory testing is recorded in order to track a patient’s progress over time. In cases with persistent symptoms, trigeminal nerve microsurgery may be indicated. Surgery entails isolating the affected nerve, removing adherent scar tissue, and occasionally excising a fibrotic portion of the nerve with direct neurorrhaphy. When a large continuity defect is present, a nerve graft may be indicated. Methods: A comprehensive literature review was conducted on the etiology, diagnosis, and treatment of trigeminal nerve injuries. Multiple databases were used to find relevant articles, including PubMed and MEDLINE. Conclusions: Trigeminal nerve injuries occur infrequently in oral and maxillofacial surgery, but such injuries can be worrisome for patients and providers alike. Thankfully, trigeminal nerve microsurgery has the potential to provide affected patients with improved functional sensory recovery and quality of life.