ACCURACY OF DIGITAL MODELS USING AMERICAN BOARD CAST-RADIOGRAPHIC EVALUATION

Abstract

Objective: To assess the accuracy of the OrthoCAD software (version 5.4) compared to conventional plaster casts in measuring the ABO Cast-Radiographic Evaluation.Material and Methods: Forty post-treatment plaster cast were randomly selected from the University at Buffalo Orthodontics postgraduate program and scanned by iTero element (Align Technology, Inc. San Jose, CA) to produce forty corresponding digital casts. The plaster models were scored by using the ABO measuring gauge using the ABD Cast-Radiographic evaluation guidelines. The digital models were measured by the ABO Phase III grading tool using OrthoCAD software version 5.4. Data were analyzed using paired student t-test.Results: Intraexaminer reliability was found to be highly reliable for all plaster cast measurements (ICC>0.820, p<.05) except occlusal relationships which showed poor intraexaminer reliability (ICC=0.480, p=0.138). A significant P value of 0.05 was used for each test. Based on the P values, it was concluded that the total score (p<0.001), alignment (p= 0.023), buccolingual inclination (p= 0.007), overjet (p=0.054), occlusal contacts (p<0.001), and occlusal relationship (p= 0.002) were statistically significantly different between plaster and digital models. For marginal ridge and interproximal contact there were no statistically significant difference between plater and digital models with a p-value of 0.746 and 0.07 respectively. Conclusion: The OrthoCAD software version 5.4 should be used with caution because its result was not adequate for scoring C-R Eval as required by the ABO.