Occlusal outcome after orthodontic treatment with preadjusted straight-wire and standard edgewise appliances: A retrospective cohort study

PURPOSE: Orthodontic fixed appliances have been proven to be effective in treating a wide variety of malocclusions, and different types of appliances have emerged during recent decades. However, the comparative effects of different appliances have not been adequately assessed. Thus, the aim was to assess the occlusal outcome of orthodontic treatment with preadjusted straight-wire (SWIRE) and standard edgewise (SEDGE) appliances. METHODS: In all, 56 patients (mean age: 13.5 years; 45% male) receiving extraction-based treatment with either SWIRE or SEDGE appliances were included. Between-group differences in the occlusal outcome assessed with the American Board of Orthodontists Objective Grading System (ABO-OGS) and treatment duration were analyzed statistically at the 5% level. RESULTS: The average ABO-OGS score was 31.3 ± 7.2 points and 34.0 ± 10.4 points in the SWIRE and SEDGE groups with no statistically significant difference between groups (P = 0.26). Treatment duration was significantly shorter in the SWIRE group compared to the SEDGE group, with an average difference of −6.8 months (95% confidence interval [95% CI] = −9.6 to −4.0 months; P < 0.001). Likewise, fewer visits were needed with SWIRE compared to SEDGE appliances with an average difference of −7.2 visits (95% CI = −10.3 to −4.2 visits; P < 0.001). Adjusting for the influence of any potential confounders did not considerably impact the results. CONCLUSION: Similar treatment outcomes were observed after premolar extraction treatment with SWIRE and SEDGE appliances. On the other hand, SEDGE appliances were associated with prolonged treatment duration and more visits needed to complete treatment compared to SWIRE appliances. SUPPLEMENTARY INFORMATION: The online version of this article (10.1007/s00056-020-00273-z) contains supplementary material, which is available to authorized users.