The effect of two low-level laser irradiation protocols on molar anchorage loss (A randomized controlled clinical trial)

Objective: Low-level laser therapy (LLLT) has been found to accelerate the rate of tooth movement, which in turn may aid in preserving posterior anchorage. However, one of the drawbacks of LLLT, is the high frequency of patient recall. The aim of the study was to evaluate and compare the amount of molar anchorage loss accompanying canine retraction, by employing two LLLT protocols, involving a high and a low application frequency. Materials and Methods: Sixteen patients were enrolled, in which the therapeutic extraction of maxillary 1st premolars was required for orthodontic treatment, with subsequent canine retraction. Patients were equally and randomly divided into 2 groups. In Group A, LLLT was randomly administered to one side of the maxillary arch on days 0, 3, 7, 14, and then every 2 weeks, while in Group B, one side of the maxillary arch was randomly selected for LLLT application every 3 weeks. The administered LLLT was a Diode laser with a 980 nm wavelength. Canine retraction was carried out using closed-coil springs, with 150 grams of force, and the amount of mesial molar movement was checked every 3 weeks, over the 12-week study period. Results: Equivalent amounts of mesial molar movements have been displayed with and without LLLT application, in both study groups. Also, no significant differences have been documented between the laser sides in groups A and B. Conclusion: Molar anchorage has not been augmented by LLLT, whether applied with a high frequency, or with less frequent applications coinciding with the follow-up visits.