The effect of low-level laser radiation on improving inferior alveolar nerve damage after sagittal split osteotomy: a systematic review.

Inferior alveolar nerve (IAN) damage is a common complication occurring after sagittal split osteotomy (SSO) and results in sensory disorders of the jaw region. In recent years, published experimental and clinical evidence suggests that low-level laser (LLL) radiation is effective in nerve recovery. Therefore, the aim of the present study was to review clinical trial studies investigating the effect of LLL radiation on improving the sensory defects of IAN after SSO. The keywords associated with SSO and LLL were searched in PubMed, Medline (via Ovid), Web of Science (WOS), Scopus, and Cochrane Library databases. Then, controlled clinical trial studies published before November 2017 regarding LLL radiation conducted on patients with IAN neuropathy due to SSO were investigated. The articles fulfilling the study criteria were further scrutinized and the necessary information was extracted from them. A total of seven papers were included in the study. The diode laser used had a wavelength range of 760-930 nm, radiation power of 20-200 mw, and radiation energy of 10.2-95 J (per point of radiation). In the mentioned studies, the patients underwent 3-20 sessions of laser irradiation and were monitored for an additional 0-23 months after completion of the laser intervention. The tests performed in the mentioned studies dealt with examining the perceptions of superficial touch and pressure, two-point discrimination, stimulus movement on skin, temperature, and pain. Furthermore, the patients' general awareness regarding sensory perception in the mandibular region was gauged. In six studies, laser irradiation caused relative improvement in the IAN sensory disorder for a subjective test as well as for one or more objective tests. In the reviewed clinical trial studies, LLL was generally found to be effective in improving the IAN sensory disturbance resulting from SSO, though there was no placebo effect.