The Effect of Laser Diode 940 nm on Decreasing Oropharyngeal Pain After Bimaxillary Orthognathic Surgery: A Double-Blind Randomized Trial Study

Background: Due to its invasiveness and length, bimaxillary orthognathic surgery causes highly excruciating pain in the oropharyngeal area for the patient. There are several ways to reduce this pain, including prescribing painkillers and anti-inflammatory drugs. The aim of this study was to evaluate the effect of photobiomodulation by a 940-nm laser on reducing pain in the oropharyngeal area after bimaxillary orthognathic surgery. Methods: This randomized clinical trial study was performed on 40 patients aged 17-40 years who were candidates for bimaxillary orthognathic surgery referred to the Department of Oral and Maxillofacial Surgery of Besat hospital in 2021. All patients in the intervention group underwent the photobiomodulation of the oropharyngeal area with a 940-nm diode laser immediately after the end of bimaxillary orthognathic surgery. Sore throat, jaw pain, pain when swallowing, and stridor were recorded in the first to fifth days after surgery. Finally, changes in the mean score of indices were compared within and between the two groups using repeated measure analysis of variance. Results: The mean age of patients in the intervention and control groups was 22.4±4.38 and 25.15±5.48 years, respectively (P=0.09). The pain score in the four areas studied in both intervention and control groups had a decreasing trend over time, which was statistically significant (P<0.001). In addition, the difference in the trend between the two groups was statistically significant so that in the intervention group, the decreasing trend was more severe (P<0.05). Eventually, a significant interaction was observed between the type of intervention and time in all four areas (P<0.05). Conclusions: The results showed that the use of a 940-nm diode laser led to a significant reduction in all four areas of sore throat, pain when swallowing, and stridor after bimaxillary orthognathic surgery.