Can Invisalign's Clincheck Models Accurately Predict the Treatment Outcome?

Objectives: Using the ABO's objective grading system (OGS), this study compared the 3D Clincheck models (CM) with the subject's actual 3D post-treatment models (AM). Methods: This within-subject prospective study includes 45 consecutively treated Invisalign cases. Seven components of the OGS were evaluated; deductions were given for alignment, marginal ridges, buccolingual inclination, occlusal contacts, occlusal relationships, overjet, and interproximal contacts. An overall OGS deduction score was also calculated. To eliminate observer bias, each of the seven components for both CM and AM were automatically measured using Motion View Insight 3D and MeshLab software. Results:  These preliminary results are based on the CM and AM of the first 21 cases completed. A majority (81%) of the AM showed passing (a score of 20 or less) or non-failing OGS scores (a score less than 30), compared to 95% of the CM. The percentage of non-failing scores were significantly (p=.005) higher for the CM than the AM. Compared to the AM, the CM also showed significantly (p=.016) fewer overall OGS deductions (24.6 vs 15.2).  These overall differences were due to significantly (p<.05) poorer alignment (4.1 vs 1.5 deductions), greater buccolingual inclinations (3.8 vs 2.8 deductions), less occlusal contacts (2.2 vs 4.7 deductions), and poorer occlusal relations (3.5 vs 2.2 deductions). Correlations between the CM and AM ranged from 0.44-0.71; alignment and overjet showed no significant correlations between the CM and AM. Conclusions: The Clincheck models do not accurately reflect the occlusion, as measured by the OGS, produced at end of active treatment. This project was partially supported by the Baylor Oral Health Foundation and Align Technology, Inc.