Efficiency of Aligners in Correcting Anterior Open Bite: A Systematic Literature Review

Abstract

Background: The utilization of orthodontic aligners for treating various malocclusions has significantly increased in recent years. However, there is uncertainty regarding the evidence supporting their effectiveness in correcting anterior open bite. Objective: The purpose of this study was to systematically review the literature and evaluate the clinical effectiveness of clear aligners in correcting anterior open bite based on the available evidence. Materials and methods: A total of three databases (Pubmed, Sciences Direct and Google Scholar) were searched until March 2023, in addition to a manual search in the following journals: the American Journal of Orthodontics and Dentofacial Orthopedics, The Angle Orthodontist, and the European Journal of Orthodontics. Prospective and retrospective studies assessing the ability of aligners in achieving incisal extrusion and molar intrusion movements published during the last 10 years in English were eligible to be selected. Study selection and data extraction were undertaken independently by two reviewers. Risk-of-bias (RoB) assessment was evaluated using the study quality assesment tool of NHLBI, NIH. The reporting of this review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Results: Nineteen relevant articles were included in the analysis, comprising four prospective non-randomized and fifteen retrospective non-randomized studies. Among these, four studies compared the efficacy of aligners versus fixed appliances in correcting anterior open bite, while fourteen papers evaluated the overall effectiveness of aligners in treating this malocclusion. The risk of bias was categorized as high in one study, moderate in eight studies, and low in ten studies. Extrusion was found to be easily achievable with aligners, with the actual quantity of extrusion often surpassing predictions in the majority of studies. The mean reported extrusion amounted to 1.8mm. Additionally, the mean reported intrusion was 0.75mm. Conclusion: It is evident that aligners are an effective option for the treatment of anterior open bite, this effectiveness is achieved by combining the extrusion and palatal tipping of the anterior segments with the intrusion of the lateral segments, resulting in a counterclockwise rotation of the mandible. Moreover, aligner treatment may be a valid alternative to conventional orthodontic therapy, but it does not appear to provide better control over the vertical dimension compared to fixed orthodontic appliances in adult patients.