Inferior alveolar nerve injury after sagittal split osteotomy of the mandible: A literature review

Abstract

Background

Inferior alveolar nerve (IAN) injury is a serious potential complication of orthognathic surgery because the osteotomy cut-line during sagittal split osteotomy (SSO) of the mandible runs close to the mandibular canal. According to statistics, 9%–85% of patients who undergo such surgery suffer from complications. It causes neurosensory disorders (NSD) of the lower lip and chin with a wide variety of symptoms such as numbness, hypoesthesia, hyperesthesia, hypoalgesia, hyperalgesia, and allodynia. However, the accurate planning and thorough analysis using cone-beam computed tomography helps improve the predictability of possible IAN damage by considering the specific anatomical features of each patient and all risk factors. This study aimed to review the frequency of IAN occurrence, risk factors, and diagnostic, prophylactic, and treatment methods used for inferior alveolar nerve regeneration and IAN sensory disturbance recovery following SSO of the mandible.

Methods

We conducted a comprehensive literature search (2020–2024) across PubMed, Scopus, Google Scholar, and ScienceDirect, focusing on mandibular SSO complications, IAN damage, nerve regeneration, and treatments such as corticosteroids, vitamin B12, platelet concentrates, and low-level laser therapy. All systematic review, randomized controlled trial, controlled clinical trial, or retrospective/prospective study involving both animals and humans were included.

Results

Surgeons prescribed medicines for general therapy before surgery and applied intraoperative treatment methods to minimize the degree of NSD manifestation after surgery. Fortunately, majority instances of NSD recover spontaneously by 6 months after the operation; however, if symptoms persist after 1 year, it is considered permanent NSD, which may cause a significant decrease in quality of life. In the postoperative period, assessing neurosensory disturbances with subjective (questionnaires) and objective tests (light touch, 2-point discrimination tests, and others), or their combination, is necessary for determining the management. According to recent studies, dexamethasone, a complex of vitamin B, melatonin, and low-level lasers, is actively used in inferior alveolar nerve regeneration during and after SSO. Moreover, isolated studies have reported the intraoperative use of platelet concentrates during SSO.

Conclusion

The mentioned treatment methods demonstrated positive results in decreasing NSD. However, their effectiveness for IAN regeneration has not been sufficiently studied.