A Comparative Analysis of Orthognathic Surgical Stability between Fixed Appliances and Clear Aligner Orthodontic Therapy

Abstract

BackgroundSkeletal relapse etiology in orthognathic surgery (OGS) is multifactorial. The role of differing orthodontic mechanics, such as fixed appliances and clear aligners in relapse, has not been explored. The adoption of clear aligner orthodontic therapy in surgical-orthodontic cases is slow due to concerns regarding surgical protocol and postoperative stability. Patients seeking surgical orthodontic treatment with clear aligner therapy is increasing, and outcomes require investigation. ObjectiveThe study's objective is to compare the degree of skeletal relapse in the sagittal and vertical dimension following OGS between cases managed with fixed appliance and clear aligner orthodontic therapy. MethodologyA retrospective chart review was conducted to include patients undergoing OGS with surgical-orthodontic therapy. The intervention group consisted of patients with clear aligner orthodontic therapy. The matched-control group was comprised of patients treated by conventional fixed appliances and were selected based on corresponding age, sex, medical status, and surgical treatment plan to the intervention group. A lateral cephalogram with standard cephalometric analysis was obtained at 2 postoperative time periods: within 7 days (T1) and 1 year (T2), postoperatively. Differences in linear and angular references were calculated. The degree of skeletal relapse measured the difference between the 2 time periods. Statistical analysis: parametric method with standard T-tests and a significance level of .05. ResultsTwenty-six orthognathic surgery patients were included in the study: 13 patients treated by fixed appliances (control) and 13 patients treated by clear aligner therapy (intervention). There was no statistically significant difference in age or surgical movement (P < .05) between the 2 groups; 18 patients had bimaxillary surgery, and 8 had single-jaw surgery (6 BSSO and 2 Le Fort). The mean surgical movements were 4.13mm advancement and 0.44mm impaction in the maxilla, with a 1.3mm setback in the mandible. Cephalometric analysis in the control group demonstrated a -0.20mm posterior relapse of A point and a -0.28mm relapse of B point. Angular measurement differences of SNA and SNB were -1.4 and -2.3, respectively. In the intervention group, cephalometric analysis revealed skeletal relapse between the time periods of a -0.22mm posterior relapse of A point and a -0.31mm of B point occurred. Angular changes of SNA and SNB were -1.1 and -1.9, respectively. There was no statistically significant difference in surgical relapse between both groups. ConclusionThe results of this study demonstrate that skeletal relapse following OGS may not be affected by the mechanism of orthodontic therapy. Both fixed orthodontic appliances and clear aligner therapy patients displayed minimal postoperative skeletal changes. Although a small sample size, this initial evaluation does provide support in the use of clear aligner orthodontic therapy as a viable treatment option in surgical orthodontics.