Reliability assessment of the non-rigid registration for central incisors movement evaluation based on CBCT registration

In order to solve the problems of magnification and contouring errors in the lateral cephalogram registration method, we have explored a new method to improve the accuracy of lateral cephalogram registration, and we aimed to evaluate its reliability with the results of CBCT registration. We selected cephalometric data from 100 patients, including lateral cephalograms and CBCT data before and after treatment; half underwent premolar extraction, and the others did not. The movement of the upper and lower central incisors was assessed using two registration methods. Finally, we compared the two registration methods to evaluate the reliability of the two-dimensional registration. The results suggested the difference values between the results of the two registration methods ranged from 0.49 to 0.76 mm. The results of the Wilcoxon signed-rank test and t-test suggested that there were no significant differences between the two registration methods when evaluating the movement distance of the upper and lower central incisors. The maximum correntropy-based iterative closest point algorithm with scale successfully addresses magnification issues and contouring errors in lateral cephalogram registration. This registration method is reliable for evaluating the movement distance of the upper and lower central incisors.