Evaluation of fixed and removable habit-breaking appliances for overbite correction in tongue thrust–associated anterior open bite: a systematic review and meta-analysis

Purpose To evaluate the effects of fixed and removable habit-breaking appliances on overbite correction in tongue-thrust-associated anterior open bites.Methods Searches were conducted in MEDLINE, Embase, CENTRAL, Scopus, Web of Science, and grey literature up to December 2025. Randomized and non-randomized controlled studies involving children and adolescents with tongue-thrust-associated anterior open bites were included. The interventions included fixed and removable habit-breaking appliances. The primary outcome was overbite change. Subgroup analyses were used to assess appliance type, age, stability, and spontaneous changes. The risk of bias was evaluated using RoB 2 and ROBINS-I, and the evidence certainty was evaluated using GRADE. Random-effects meta-analyses were performed, as appropriate.Results Eleven studies were included in this meta-analysis. The pooled analysis suggested greater overbite improvement with habit-breaking appliance therapy compared with untreated controls. Fixed and removable appliances showed comparable effects, with no significant differences between the types. Greater effects were observed in younger patients. Overbite correction was maintained during follow-up, whereas the untreated controls demonstrated spontaneous growth-related improvement. The overall evidence certainty was very low.Conclusion Habit-breaking appliances may improve overbite in patients with tongue thrust–associated anterior open bite; however, the certainty of the available evidence is very low, and the findings should be interpreted cautiously.