Equivalence of virtual and physical model surgery on digitally fabricated models for occlusal planning in segmental...

Maxillary segmentation is often necessary to achieve optimal occlusion in orthognathic surgery, and although virtual surgical planning provides improved diagnostic precision and workflow efficiency, many surgeons continue to rely on conventional model surgery for establishing occlusion in segmented cases, with limited evidence directly comparing these approaches. This in-vitro study evaluated archived, de-identified preoperative intraoral scans of patients who underwent segmental maxillary orthognathic surgery at the University of Texas Health Science Center at San Antonio, including only cases requiring a three-piece maxillary osteotomy and excluding patients with partial edentulism or cleft palate. The method used to obtain the occlusion-either physical model surgery performed on digitally fabricated models or virtual model surgery-served as the predictor variable, and the primary outcome was equivalence of the final occlusal result. Two surgeons independently performed both techniques in 20 cases, generating a total of 80 final occlusions. Dimensional analysis using surface-based best-fit registration demonstrated a mean three-dimensional occlusal deviation of 0.03 mm between workflows, which was well below the predefined tolerance threshold of 0.3 mm. Parametric statistical analysis showed no significant differences between occlusal outcomes produced by the two methods. These findings indicate that virtual model surgery is clinically feasible and produces occlusal results equivalent to conventional model surgery in segmental maxillary procedures, supporting its use as a reliable alternative for preoperative planning.