Spyridon N Papageorgiou1, Despina Koletsi1, Anna Iliadi2, Timo Peltomaki3,4,5, Theodore Eliades1. 1. Clinic of Orthodontics and Pediatric Dentistry, Center of Dental Medicine, University of Zurich, Zurich, Switzerland. 2. Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, Greece. 3. Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland. 4. Department of Ear and Oral Diseases, Tampere University Hospital, Tampere, Finland. 5. Faculty of Health Sciences, University of Eastern Finland, Kuopio, Finland.
Abstract
BACKGROUND: The use of orthodontic aligners to treat a variety of malocclusions has seen considerable increase in the last years, yet evidence about their efficacy and adverse effects relative to conventional fixed orthodontic appliances remains unclear. OBJECTIVE: This systematic review assesses the efficacy of aligners and fixed appliances for comprehensive orthodontic treatment. SEARCH METHODS: Eight databases were searched without limitations in April 2019. SELECTION CRITERIA: Randomized or matched non-randomized studies. DATA COLLECTION AND ANALYSIS: Study selection, data extraction, and risk of bias assessment was done independently in triplicate. Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted, followed by sensitivity analyses, and the GRADE analysis of the evidence quality. RESULTS: A total of 11 studies (4 randomized/7 non-randomized) were included comparing aligners with braces (887 patients; mean age 28.0 years; 33% male). Moderate quality evidence indicated that treatment with orthodontic aligners is associated with worse occlusal outcome with the American Board of Orthodontics Objective Grading System (3 studies; MD = 9.9; 95% CI = 3.6-16.2) and more patients with unacceptable results (3 studies; RR = 1.6; 95% CI = 1.2-2.0). No significant differences were seen for treatment duration. The main limitations of existing evidence pertained to risk of bias, inconsistency, and imprecision of included studies. CONCLUSIONS: Orthodontic treatment with aligners is associated with worse treatment outcome compared to fixed appliances in adult patients. Current evidence does not support the clinical use of aligners as a treatment modality that is equally effective to the gold standard of braces. REGISTRATION: PROSPERO (CRD42019131589).
BACKGROUND: The use of orthodontic aligners to treat a variety of malocclusions has seen considerable increase in the last years, yet evidence about their efficacy and adverse effects relative to conventional fixed orthodontic appliances remains unclear. OBJECTIVE: This systematic review assesses the efficacy of aligners and fixed appliances for comprehensive orthodontic treatment. SEARCH METHODS: Eight databases were searched without limitations in April 2019. SELECTION CRITERIA: Randomized or matched non-randomized studies. DATA COLLECTION AND ANALYSIS: Study selection, data extraction, and risk of bias assessment was done independently in triplicate. Random-effects meta-analyses of mean differences (MDs) or relative risks (RRs) with their 95% confidence intervals (CIs) were conducted, followed by sensitivity analyses, and the GRADE analysis of the evidence quality. RESULTS: A total of 11 studies (4 randomized/7 non-randomized) were included comparing aligners with braces (887 patients; mean age 28.0 years; 33% male). Moderate quality evidence indicated that treatment with orthodontic aligners is associated with worse occlusal outcome with the American Board of Orthodontics Objective Grading System (3 studies; MD = 9.9; 95% CI = 3.6-16.2) and more patients with unacceptable results (3 studies; RR = 1.6; 95% CI = 1.2-2.0). No significant differences were seen for treatment duration. The main limitations of existing evidence pertained to risk of bias, inconsistency, and imprecision of included studies. CONCLUSIONS: Orthodontic treatment with aligners is associated with worse treatment outcome compared to fixed appliances in adult patients. Current evidence does not support the clinical use of aligners as a treatment modality that is equally effective to the gold standard of braces. REGISTRATION: PROSPERO (CRD42019131589).