Figure 3. Overall pooling for occlusal outcomes of fixed appliance (FA) treatment assessed using the Orthodontic Grading System proposed by the American Board of Orthodontics Mean Orthodontic Grading System scores and their corresponding 95% confidence intervals (CIs) for each included study are given as boxes with horizontal lines, respectively. The weighted pooled summary estimates with and their corresponding 95% CIs for the two subgroups or overall are given as diamonds. Horizontal lines at the diamonds represent the 95% prediction that gives a range of possible values to be clinically seen, while incorporating existing heterogeneity.