Aim: The present study aimed to develop a method for measuring 3D maxillary tooth movement during orthodontic treatment and to verify the accuracy of the method.
Materials and methods: A 3D model analysis method was established to measure tooth movement by combining the effects of CBCT and intraoral scans. Transformation matrices were used to abstract the motion features of the teeth and translate them into translations and rotations. To test the validity and reliability of the method for clinical application, the inclination of the central incisor was measured using a 3D model analysis method and cephalometric analysis. Measurement error, correlation, and agreement between the two methods were analyzed using the Dahlberg formula, intraclass correlation coefficient, and Bland-Altman analysis, respectively. The performance of the 3D model analysis method was evaluated by monitoring the canine movement of a patient who underwent a premolar extraction.
Results: The measurement error was 0.58 degrees for the 3D model analysis and 2.02 degrees for the cephalometric analysis. There was no significant difference in the central incisor inclination measurements between the cephalometric and the 3D model analyses methods. A high correlation (0.974) and narrow limits of agreement (-3.55 degrees, 4.16 degrees) were obtained between the two methods. Minute movements and additional details of orthodontic tooth movements could be observed using the 3D model analysis method.
Conclusion: The 3D model analysis method was reliable and reproducible for clinical application in monitoring the 3D maxillary tooth movement during orthodontic treatment. The trueness should be further evaluated. (Int J Comput Dent 2023;26(1): 49-0; doi: 10.3290/j.ijcd.b3818301).
Keywords: computed tomography; digital model; intraoral scan; orthodontic tooth movement; superimposition; transformation matrix.