Effects of tooth extraction on smile esthetics and the buccal corridor: A meta-analysis

Background/purpose: Smile esthetics is a critical factor for evaluating orthodontic treatment outcomes. The effects of tooth extraction on smile esthetics and buccal corridor remain controversial and have not been adequately investigated. Therefore, in this systematic review and meta-analysis, we evaluated the aforementioned effects. Materials and methods: We searched clinical studies held in PubMed, MEDLINE, Embase, and the Cochrane Library up to May 2015, with no restriction. Study selection and data extraction were conducted by two reviewers independently. A random-effects model was used for conducting a meta-analysis to assess the mean difference between the esthetic score and the buccal corridor ratio of extraction and nonextraction groups. Results: Six eligible studies were included in this meta-analysis. No significant difference was observed in the esthetic score and the buccal corridor ratio between extraction and nonextraction groups. Conclusion: Tooth extraction does not affect smile esthetics or buccal corridor. However, additional detailed, large-scale, double-blinded, and randomized controlled trials are required for further evaluation.