Abstract
BACKGROUND: To evaluate the effectiveness of two minimally invasive surgical procedures in the acceleration of canine retraction: piezocision and laser-assisted flapless corticotomy (LAFC). METHODS: Trial design: A single-centre randomized controlled trial with a compound design (two-arm parallel-group design and a split-mouth design for each arm). PARTICIPANTS: 36 Class II division I patients (12 males, 24 females; age range: 15 to 27 years) requiring first upper premolars extraction followed by canine retraction. INTERVENTIONS: piezocision group (PG; n = 18) and laser-assisted flapless corticotomy group (LG; n = 18). A split-mouth design was applied for each group where the flapless surgical intervention was randomly allocated to one side and the other side served as a control side. OUTCOMES: the rate of canine retraction (primary outcome), anchorage loss and canine rotation, which were assessed at 1, 2, 3 and 4 months following the onset of canine retraction. Also the duration of canine retraction was recorded. Random sequence: Computer-generated random numbers. Allocation concealment: sequentially numbered, opaque, sealed envelopes. Blinding: Single blinded (outcomes' assessor). RESULTS: Seventeen patients in each group were enrolled in the statistical analysis. The rate of canine retraction was significantly greater in the experimental side than in the control side in both groups by two-fold in the first month and 1.5-fold in the second month (p < 0.001). Also the overall canine retraction duration was significantly reduced in the experimental side as compared with control side in both groups about 25% (p ≤ 0.001). There were no significant differences between the experimental and the control sides regarding loss of anchorage and upper canine rotation in both groups (p > 0.05). There were no significant differences between the two flapless techniques regarding the studied variables during all evaluation times (p > 0.05). CONCLUSIONS: Piezocision and laser-assisted flapless corticotomy appeared to be effective treatment methods for accelerating canine retraction without any significant untoward effect on anchorage or canine rotation during rapid retraction. TRIALS REGISTRATION: ClinicalTrials.gov (Identifier: NCT02606331 ).