Fig. 2

Scatterplots of predicted values versus achieved values for lower incisor tip, mesio-distal movement of root apex and incisal edge movements. Scatterplot data (charts to the left) were fitted using linear regression analysis and the regression coefficients are given in the charts, including the coefficient of determinations (R²). The best linear fitting was obtained from the mesio-distal movement of incisal edge (R² = 0.73), while the association between predicted and observed values was weaker for the lower incisor tip and the movement of root apex with R² values of 0.55 and 0.54, respectively. Bland–Altman plots were used to describe systematic differences between predicted and observed measurements. The difference between each pair of predicted and observed values was plotted against their mean value. This allowed estimate the mean bias between predicted and observed values and their upper and lower 95% limits of agreement (LoA)