Effect of low-level laser therapy on pain reduction in orthodontic patients during molar distalization: A randomized controlled trial

Aim: To investigate the effects of low-level laser therapy (LLLT) on pain reduction in orthodontic patients during molar distalization. Materials and methods: Twenty patients requiring bilateral maxillary first molar distalization were randomly assigned to two groups: the intervention group (mean age 15.61 ± 1.03 years) received multiple LLLT after every activation of the distalizing appliance (immediately and on the 3rd, 7th, and 14th days) and the control group (mean age 15.64 ± 1.08 years) who did not receive LLLT. Patients reported pain levels every day for 7 days following activation of the appliance using an 11-point numeric rating scale (NRS), then the pain experience of both the intervention and control groups was compared using Mann-Whitney U test. Results: The mean pain scores on the 1st day were higher in the intervention group (9.27 ± 1.01) compared to that of the control group (8.80 ± 1.03). However, the mean pain scores of the intervention group (6.55 ± 1.29, 4.00 ± 1.26, 2.55 ± 1.29, 0.91 ± 1.04, 0.00 ± 0.00 and 0.00 ± 0.00, respectively) were lower than the control group (7.40 ± 1.90, 5.60 ± 2.07, 4.20 ± 1.99, 2.80 ± 1.93, 1.60 ± 1.58 and 0.40 ± 0.84, respectively) from the 2nd to the 7th day. All the differences were not statistically significant except on the 6th day (P-value = 0.003). The peak pain level was experienced by both groups on the 1st day, followed by a statistically significant gradual decrease in pain levels. Patients in the intervention group reported a shorter overall duration of pain. Conclusion: Although LLLT, with the used parameters, reduced the overall duration of pain experience following maxillary first molar distalization, it was not effective during peak pain levels.