Effect of photobiomodulation on recovery from neurosensory disturbances after sagittal split ramus osteotomy: a triple-blind randomised controlled trial.

We have investigated the effect of photobiomodulation on the recovery of neurosensory function of the lip and chin after bilateral sagittal split osteotomy (BSSO). Laser irradiation was applied with a GaAs diode laser (continuous wave 980nm wavelength, power 100mW, and energy density 12J/cm). It was maintained within a 0.5cm area in a total of 12 points for 60seconds at each visit on each point. Unilateral extraoral contact photobiomodulation treatment was applied the day before operation and then on days 1, 3, 7, 14, 21, and 28 postoperatively. One side of the mandible was the intervention side and the other the control side. On the control side, the laser probe was turned off and placed on the chosen area. Neurosensory evaluations were made before and immediately after operation, and 30 days and 60 days postoperatively. Twenty-five patients were screened, and 18 who met the inclusion criteria were included in the study; 14 were women and the mean (SD) age was 23 (5) years. Analysis of the visual analogue scales for general sensibility, pain discrimination, directional discrimination, and 2-point discrimination showed a significant difference between the intervention and control sides after 30 days (p=0.0011, 0.0034, 0.0023, and 0.0160, respectively). The difference was also significant after 60 days (p=0.0001, 0.0002, 0.0003, and 0.0010, respectively). The thermal discrimination rate was significantly higher in the laser group than the control group 30 days after surgery (p=0.002), but after 60 days the difference was not significant (p=1.000). We found no side effects from the laser radiation during the two-month follow up. The results suggest that photobiomodulation accelerated the patients' improvement from neurosensory disturbance after BSSO.