Comparison of Upper and Lower Canine Retraction Rates Assisted by Flapless Laser Corticotomy.

Introduction: One of the most frequent issues in extraction cases is the prolonged duration of orthodontic therapy and the slow rate of canine retraction. Aim: This secondary analysis study aimed to compare the rate of canine retraction in upper and lower canines facilitated with Flapless Laser corticotomy (FLC). Materials and Methods : The study included 56 canines from 14 patients (2 males /12 females) with a mean age of (20.4±2.5) years diagnosed with bimaxillary dentoalveolar protrusion and treated with 4 premolars extraction with upper and lower fixed appliances. The intervention was applied in a split-mouth fashion, so before commencing the study, 2 random computer-generated lists with a 1:1 allocation ratio were obtained to detect the side of intervention, these lists were concealed in opaque envelopes until the time of intervention. All participants were allocated into 2 groups, I-(Maxillary canines: which were divided into two subgroups A. Control, B. FLC) and II-(Mandibular canines: which were divided into two subgroups A. Control B. FLC). FLC was applied on the experimental sides before canine retraction by performing 6 holes with 3 mm of depth into the alveolar bone on both mesial and distal sides of all canines, then canines’ retraction was performed using closed-coil springs to obtain a force of 150 gm while anchorage was augmented indirectly with TADs. The rate of canine retraction was assessed at T0, T1, T2, and T3 (just before, 1 month, 2 months, and 3 months after retraction), using 3-Dimentional digital casts. Only the statistical analysis expert was blinded. Results: The results showed a statistically non-significant difference between all groups (upper and lower flapless laser corticotomy and control) in the change in canine retraction distance and monthly rate of Canine retraction. Conclusion: There were neither statistically nor clinically significant differences between upper and lower canine retraction rates either by conventional method or assisted by FLC performed in this study.