Analysis of canine retraction and anchorage loss in different facial types with and without piezocision: a split-mouth-design, randomized clinical trial

Objectives: To investigate canine retraction (CR) and anchorage loss (AL) among average facial height (AFH) and high facial height subjects (HFH) with or without piezocision surgery (PS). Materials and Methods: This was a split-mouth, randomized clinical trial. Twenty-three females (aged 19.05 +/- 2.95 years) who presented with Class II division I malocclusion requiring bilateral maxillary extraction and who fulfilled eligibility criteria were included and categorized into two groups: AFH (12 participants) and HFH (11 participants). Atraumatic extractions were performed 10 weeks following bonding. Before space closure, impressions were taken to fabricate models, which were scanned to generate digital models. Each participant had PS on the randomly assigned side. Space closure was undertaken using 100-g nickel-titanium coil closing springs on 0.019 x 0.025-inch stainless steel archwire. Digital models were collected 6 and 12 weeks post-PS. They were superimposed using reliable reference points and a region of interest on the palate, and crown movements were analyzed in three dimensions. Results: Three months post-PS, intergroup comparisons showed that rates of CR for control sides (mean = 1.88 +/- 0.83 mm for AFH, mean = 1.76 +/- 0.62 mm for HFH) and intervention sides (mean = 1.48 +/- 0.74 mm for AFH, mean = 1.40 +/- 0.85 mm for HFH) were not significantly different. AL was not significantly different (P > .05) between groups. Conclusion: Regardless of whether the patient underwent PS, CR and AL rates for AFH and HFH patients were not significantly different.