摘要 : Objectives: To assess the effect of low-level laser therapy (LLLT) on overall leveling and alignment time of mandibular anterior crowding and associated pain after initial archwire placement. Materials and Methods: Thirty-two fema... 展开 Objectives: To assess the effect of low-level laser therapy (LLLT) on overall leveling and alignment time of mandibular anterior crowding and associated pain after initial archwire placement. Materials and Methods: Thirty-two females (18-25 years) with mandibular anterior crowding were randomly allocated into laser and control groups. Eligibility criteria included Angle Class I molar relationship and Little's irregularity index (LII) from 4 to 10 mm. Randomization was accomplished with a computer-generated random list. A 0.014-inch copper-nickel-titanium (Cu-NiTi) wire was inserted immediately after bonding of 0.022-inch Roth brackets followed by 0.016-inch Cu-NiTi, 0.016 3 0.022-inch NiTi then 0.017 3 0.025-inch stainless steel wire after completion of alignment. In-Ga-As laser was applied to the mandibular anterior segment in the laser group on days 3, 7, and 14, then at 1 month followed by every 2 weeks until completion of leveling and alignment. Visual analogue scale questionnaires were completed by each patient over 7 days from initial archwire placement. Digital models were used to monitor changes in the irregularity index. Blinding was applicable for outcome assessors only. Results: The mean time for leveling and alignment was significantly lower in the laser compared to the control group (68.2 +/- 28.7 and 109.5 +/- 34.7 days, respectively). The laser group displayed a significantly higher mean alignment improvement percentage as well as lower pain scores compared to the control group. Conclusions: Within the constraints of the current study, LLLT has a potential for acceleration of anterior segment alignment as well as reduction of the pain associated with placement of initial archwires. (Angle Orthod. 2022;92:478-486.) 收起