The effect of orthodontic treatment on facial attractiveness: a systematic review and meta-analysis.

BACKGROUND Facial and smile attractiveness are significant motivating factor for patients to seek orthodontic treatment. Although there is a general belief that orthodontic treatment improves facial appearance, this has yet not been systematically evaluated. OBJECTIVE The objective of this study was to assess the current evidence on the effect of orthodontic treatment on facial attractiveness. SEARCH METHODS Systematic and unrestricted search of nine databases were performed up to January 2022. SELECTION CRITERIA Studies evaluating facial attractiveness before and after orthodontic treatment. DATA COLLECTION AND ANALYSIS Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality, and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomized studies and with RoB-2 for randomized controlled trials (RCTs). Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were performed. RESULTS Twenty studies were included in data synthesis; three randomized controlled clinical trials and 17 non-randomized clinical studies of retrospective or prospective design. One of the RCTs was found to have low risk of bias, one presented some concerns and the third showed a high risk of bias. All non-randomized studies showed either unclear or high risk of bias. Data syntheses showed that orthodontic treatment improved facial attractiveness ratings by 9% when compared with untreated controls (MD: 9.05/95% CI: 4.71; 13.39). A combination of orthodontics and orthognathic surgery also showed a positive effect of 5.5% (MD: 5.51/95% CI: 1.55; 9.47) when compared with orthodontic treatment alone. There was no difference in effect between extraction and non-extraction treatments (MD: -0.89/ 95% CI: -8.72; 6.94) or between different types of Class II correctors (MD: 2.21/95% CI: -16.51; 20.93). LIMITATIONS With the exception of two RCTs, included studies were of unclear or low quality. CONCLUSIONS Orthodontic treatment has a clinically weak effect on facial attractiveness when compared to no treatment. The same is true when a combined orthodontic/surgical treatment is compared to orthodontics alone. REGISTRATION PROSPERO #: CRD42020169904