Efficacy of photobiomodulation therapy on pain, swelling, and trismus following fixation of mandibular fractures

Craniofacial fractures pose complex medical and surgical challenges. Prolonged wound healing complicates surgical reconstruction, highlighting the need for methods to enhance tissue healing. This research evaluated the effects of photobiomodulation (PBM) therapy on edema, trismus, and pain following mandibular fracture surgery. This study was approved by the Kasturba Hospital and Kasturba Medical College Institutional Ethics Committee (IEC: 219/2022). Thirty-two participants were signed up and split into two groups, one receiving PBM. Ten 660 nm LEDs with an energy density of 9 J/cm², Power density (irradiance) of 50 mW/cm², and nine 905 nm LEDs with an energy density of 13.5 J/cm², power density (irradiance) of 75 mW/cm². With a total power of 235 mW, the total dose was 42.3 J, a spot Size of 3.8 cm², and pulsed at 156 Hz. The mandibular body and angle area were irradiated from the outer skin surface of the Jaw region. The therapy lasted for 3 min and was given for 4 consecutive days starting from the day after surgery. The present study evaluates pain thresholds using an algometer. The facial swelling was measured at two distinct points, the ear's tragus to the labial commissure (T-LC) and the outer canthus of the eye to the mandible's angle (OC-AM), using a ruler. Mouth opening was measured for trismus using a vernier calliper. There was no significant reduction in pain (−0.34 vs. −0.09; p = 0.079) or edema (T-LC: 2.44 vs. 2.13; p = 0.771, OC-AM 2.31 vs. 0.69; p = 0.185) in the PBM-treated group compared to the control group. However, trismus reduction was significantly better in the PBM group (−3.25 vs. −1.31; p < 0.001). In summary, a specific PBM protocol can effectively reduce trismus during recovery from mandibular fractures, with the potential for future optimization to address pain and edema.