Does Low-Level Laser Photobiomodulation Improve Neurosensory Recovery After Orthognathic Surgery? A Clinical Trial With Blink Reflex

Abstract

Purpose: Evidence shows that low-level laser therapy (LLLT) may shorten the recovery time of healing wounds. This study sought to assess the effect of LLLT on the recovery time of neurosensory deficits after Le Fort I osteotomy and bilateral sagittal split osteotomy using the blink reflex. Methods: This randomized double-blind clinical trial evaluated 12 patients undergoing orthognathic surgery of the maxilla/mandible. One random quadrant of the maxilla/mandible underwent 810 nm gallium-aluminum-arsenide laser (infrared spectrum, 200 mW, 12 J/cm(2), 60-second irradiation time of each point, continuous-wave mode), while the laser handpiece was used in off mode for the other quadrant, postoperatively. The patients underwent LLLT at 1, 5, 10, and 14 days, postoperatively. The blink test was performed to assess the function of the trigeminal nerve, and the 2-point discrimination (TPD) test was performed to assess the recovery of the inferior alveolar nerve (IAN) and the infraorbital nerves at 30 and 90 days, postoperatively. Data were analyzed using the Mann-Whitney U test (alpha = 0.05). Results: Six women and 6 men were evaluated (mean age = 23.41 +/-? 5.03 years). Both groups showed significant improvement in function of the IAN and infraorbital nerves, postoperatively in blink reflex test (P < .05). In the TPD test, although both groups showed significant improvement of the IAN compared with the baseline (P < .05), the IAN showed significantly greater improvement by 1.1 in the laser group (P = .036). The percentage of change was significantly smaller in the laser group in R1 (by 14; P = .025) and R2C wavelengths of the IAN and in the TPD test of the IAN (by 20; P = .021), showing significantly greater improvement in laser group. Conclusions: LLLT with 810-nm diode laser can accelerate the recovery from paresthesia after orthognathic surgery. The blink reflex can be used as a quantitative index for neurosensory assessment in line with subjective clinical tests such as the TPD test. (C) 2020 American Association of Oral and Maxillofacial Surgeons