Effects of skeletal anchorage on mandibular rotation with fixed functional appliance therapy in class II malocclusion patients – A systematic review and meta-analysis

The study aimed to systematically investigate the effect of skeletal anchorage on mandibular rotation during FFA therapy during Class II correction in adolescents. The review protocol was registered under the PROSPERO database (CRD42021256690). Electronic searches of databases and screening were performed up to May 2022. Only randomized clinical trials (RCT) and non-randomized controlled trials (non-RCT) were included in the study. Revised Cochrane risk-of-bias tool for RCTs (RoB 2) and risk of bias in non-randomized studies-of interventions tool for non-RCT were used for studies. Meta-analysis was performed and a forest plot was obtained. The primary outcome was mandibular rotation. Other outcomes assessed were angles SNA, SNB, ANB, mandibular incisor proclination, and failure rates of mini-screws and mini plates. Twelve studies (eight RCTs and four non-RCTs) were included fulfilling inclusion criteria. Evidence showed a low-to-moderate risk of bias for different domains. Meta-analysis for mandibular rotation revealed a greater increase in mandibular plane angle in patients who received FFA with skeletal anchorage as compared to patients who did not receive skeletal anchorage. With or without skeletal anchorage, mandibular rotational changes during FFA therapy are similar. FFA when combined with skeletal anchorage causes more skeletal changes in sagittal parameters than conventional FFA used alone. FFA with skeletal anchorage reduces lower incisor proclination.