Three‐dimensional prediction of roots position through cone‐beam computed tomography scans‐digital model superimposition: A novel method

Abstract Objective: To validate the use of three-dimensional (3-D) surface rendering (SR) images to quantify the height of alveolar dehiscences. Materials and Methods: Twenty-four dehiscences were created on 9 incisors, 9 canines, and 6 premolars on 4 cadaver skulls. i-CAT cone beam computed tomography scans (CBCTs) were taken of each skull at .2 mm voxel size. Each dehiscence was quantified by 21 orthodontic residents using 3-D SR. The principal investigator (PI) also quantified each dehiscence using the 2-D multiplanar (MP) image and the 3-D SR image. Results: Results of this study showed an average method error of the residents as a group to be 0.57 mm with an intraclass correlation (ICC) of 0.77%. Residents' method error ranged from 0.45 mm to 1.32 mm, and the ICC ranged from 0.201% to 0.857%. Systematic error was low at −0.01 mm for the direct measurement compared with the residents' average 3-D SR at 1365 density value (DV) measurement. The 3-D SR at 1365 DV images were compared with the MP and 3-D SR images at 1200 DV, and no significant differences in measurements and low systematic error were noted. The method error of the PI was 0.45 mm, 0.45 mm, and 0.41 mm for 3-D SR at 1365 DV, 3-D SR at 1200 DV, and 2-D MP, respectively. Conclusions: 3-D SR and 2D MRP can be used to measure dehiscences of the periodontium with similar levels of accuracy.

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Three-Dimensional Simulation of Root Position Through a Combined Technique Using Cone-Beam Computed Tomography and a Digital Model

The Journal of Indian Orthodontic Society ◽

10.1177/0301574219840891 ◽

2019 ◽

Vol 53 (2) ◽

pp. 126-134

Author(s):

Udomsak Likitmongkolsakul ◽

Juthatip Aksornmuang ◽

Pruittikorn Smithmaitrie ◽

Bancha Samruajbenjakun

Keyword(s):

Computed Tomography ◽

Cone Beam Computed Tomography ◽

Three Dimensional ◽

High Accuracy ◽

Digital Model ◽

Cone Beam ◽

Average Error ◽

Simulated Model ◽

Combining Data ◽

Root Position

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.

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