The Effect of 660-nm Low Level Laser Therapy on Mandibular Lateral Movement After Orthognathic Surgery: A Randomized Phase 1 Trial

Introduction: Limited jaw motion is a common complication after orthognathic surgeries that can negatively affect the patients’ quality of life, thus it is required to be properly treated. Regarding the growing interests in laser application in density, we aimed to evaluate the effects of 660nm LLLT on mandibular lateral movements after orthognathic surgery. Materials and Methods: Twelve candidates of bimaxillary orthognathic surgery were included in a split-mouth, triple-blind phase 1 trial. On 1, 4, and 7 days after the surgery, a 660-nm diode low-level laser was applied to one facial side of patients, whereas the other side was kept untreated as placebo. Then, rightward and leftward mandibular movements from the maxillary midline were measured in millimeters (mm) on 2, 7, and 14 after the surgery. The measurements were then compared between the study groups using ANCOVA analysis. Results: Despite the constant improvement in mandibular lateral movements in both study groups, the rightward mandibular movements in LLLT group were significantly better than in placebo group on second (3.9 versus 3.2 mm, P = 0.015), seventh (5.6 versus 4.2 mm, P = 0.018), and 14th (7.1 versus 5.2 mm, P = 0.005) days after the surgery. Also, the leftward mandibular movements in LLLT group were significantly better than in placebo group on second (3.7 versus 2.1 mm, P = 0.021), seventh (4.9 versus 2.9 mm, P = 0.019), and 14th (6.7 versus 4.2 mm, P = 0.002) days after the surgery. Conclusion: LLLT can effectively improve both rightward and leftward movements of mandibular after an orthognathic surgery.