Root resorption in orthodontic treatment with clear aligners: A systematic review and meta-analysis.

The aim of this study was to investigate the external root resorption in participants receiving clear aligners and compare it with those treated with fixed appliances. Systematic review with meta-analysis. Electronic and manual search were performed, and specific inclusion and exclusion criteria were used. Data extraction and analysis were conducted by two investigators independently. The original outcome underwent statistical pooling by Review Manager 5. The quality of studies was assessed by ROBINS-I tool. A total of 11 studies were included for qualitative analysis (six in moderate risk of bias while another five in serious risk of bias), and three of them were statistically pooled in meta-analysis. The external root resorption in treatment with clear aligners was significantly lower than that with fixed appliances (SMD = -0.65, 95% CI [-0.74, -0.55], P < .01). Subgroup analysis on each quadrant of incisors was consistent with the former result. Current evidences suggest that clear aligners might not avoid root resorption, but the incidence and severity of resorption could both be lower compared with results reported by treatment with fixed appliances.