Evaluation of the Effect of Low-level Laser Therapy on Leveling Mandibular Anterior Crowding.

Objective: This study aims to evaluate the effect of low-level laser therapy (LLLT) on leveling mandibular anterior crowding and associated pain levels.

Methods: This double-blinded, parallel, randomized clinical trial included 30 participants who were randomly assigned to the laser group or the control group, with Little's irregularity index of 4-8 mm in the mandibular canine-canine region. Nickel-titanium archwires measuring 0.012 inches were tied with elastomeric ligatures and changed every 14 days throughout the leveling process. The leveling duration was recorded in days, from the bonding application to the end of leveling. Irradiation was performed at an 810-nm wavelength using a gallium-aluminum-arsenide diode laser device with a power output of 100 mW and an energy density of 8 J/cm². Laser applications were performed after archwire ligation (day 0), on days 3, 7, and 14 and every 14 days until leveling was completed. The leveling duration was calculated, and pain levels were evaluated using a visual analogue scale (VAS) after archwire ligation (hour 0), at hours 2 and 6 and on days 1, 3, 7, 14, and 21.

Results: The leveling duration showed no significant differences between the laser and control groups (p=0.170). Group comparison results of the VAS scores at hour 6 (p=0.001) and day 1 (p=0.006) exhibited significantly reduced pain levels in the laser group compared with the control group.

Conclusion: Although LLLT is not effective in reducing the leveling duration, it significantly reduces pain levels at hour 6 and on the 1^st day.