Three

Abstract Objective: The aim of this study was to develop a method to simulate root position in the patient and to evaluate the accuracy of all procedures. Materials and Methods: In Part I, the accuracy of a tooth model generated using cone-beam computed tomography (CBCT) was evaluated. Mesiodistal width was measured and compared between digital models and actual teeth. In Part II, the accuracy of simulated root positions generated in the scanned model was evaluated. Simulated root models were superimposed on the scanned dental model using the best fit method. The distances between the reference wire and the tooth were compared. In Part III, the simulated method was used with real orthodontic patients. The distances between the mini-implant and the tooth were compared. Results: Part I: The range of the differences was ？0.106 to 0.152 mm. Part II: The range of the differences between the distance of the constructed tooth model and the simulated model was ？0.065 to 0.256 mm. Part III: The range of the differences between the distance of the constructed tooth model and the simulated model was ？0.089 to 0.135 mm. This technique provided high accuracy, with an average error of only 0.054 mm. Conclusion: High accuracy of the constructed model was achieved. Simulation of root position in a patient can be accomplished by combining data from CBCT and the digital model. This technique might be used effectively in orthodontic treatment