Comparative effects of clear aligner mandibular advancement and twin block appliances in Class II malocclusion

Background: This study compared the effects of clear aligner Mandibular Advancement (MA) and Twin Block (TB) appliances on Class II malocclusion in adolescents. Methods: A retrospective analysis was conducted on 47 patients divided into three groups: 19 (11 females, 8 males; 11.19 ± 1.31 years) underwent MA treatment, 15 (6 females, 9 males; 11.86 ± 1.92 years) received TB therapy and 13 (7 females, 6 males; 11.62 ± 1.85 years) served as controls. Cephalometric analyses assessed skeletal, dental and soft tissue changes before and after treatment. Statistical methods included normality tests, intra- and inter-group comparisons (t-tests, Wilcoxon signed-rank tests, Analysis of Variance (ANOVA), Kruskal-Wallis H tests), with significance set at p < 0.05. Results: Results revealed intra-group variations in mandibular and intermaxillary relationships across all groups. The Wits appraisal showed significant differences between the TB and control groups, while the TB group exhibited increased lower anterior facial height. Intra- and inter-group differences were observed in upper incisor inclination, lower incisor proclination, overjet, and overbite. Soft tissue changes included upper lip retraction in the TB group and forward pogonion shift in the MA group. Conclusions: MA improved soft tissue chin thickness and better controlled lower facial height, making it preferable for enhancing chin profiles. Conversely, TB enhanced upper lip position and facial convexity, making it more suitable for improving upper lip aesthetics. Clinicians should consider these distinct advantages when selecting an appliance for growing Class II malocclusion patients. Clinical Trial Registration: Registered at ClinicalTrials.gov: NCT06609733.

Mandibular advancement; Clear aligner; Twin-block; Soft tissues; Class II malocclusion

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