Clinical Evaluation of Digital Dental Articulation for One-Piece Maxillary Surgery

Abstract Purpose Digital dental alignment is not readily available to automatically articulate the upper and lower models. The purpose of this study was to assess the accuracy of our newly developed 3-stage automatic digital articulation approach by comparing it to the gold standard of orthodontist-articulated occlusion. Materials and methods Thirty pairs of stone dental models from double-jaw orthognathic surgery patients who had undergone a one-piece Le Fort I osteotomy were used. Two experienced orthodontists together, hand articulated the models to their perceived final occlusion for surgery. Each pair of the models was then scanned twice: while they were in orthodontist-determined occlusion, and while the upper and lower models were separated and positioned randomly. The separately scanned models were automatically articulated to the final occlusion using our 3-stage algorithm, resulting in an algorithm-articulated occlusion (experimental group). The models scanned together represented the hand-articulated occlusion (control group). The qualitative evaluation was completed using a 3-point categorical scale by the same orthodontists, who were blinded from the methods used to articulate the models. A quantitative evaluation was also completed to determine whether there was a difference in midline, canine and molar relationship between the algorithm- and hand-articulated occlusions using repeated measures analysis of variance (ANOVA). Finally, means and standard deviations were used to present the differences between the 2 methods. Results The results of the qualitative evaluation revealed that all the algorithm-articulated occlusions were as good as the hand-articulated ones. The results of repeated measures ANOVA showed that there was no statistically significant difference between the two methods (F(1,28)=0.03, P=0.87). The mean differences between the two methods were all within 0.2mm. Conclusions The results of our study have demonstrated that the dental models can be accurately, reliably and automatically articulated using our 3-stage algorithm approach to the standards of orthodontists.