Accuracy of Hard Tissue Predictions in Mono- and Bimaxillary Orthognathic Surgery Using 3D Virtual Surgical Planning

Objectives The aim of this study was to quantify the accuracy of hard tissue predictions in three-dimensional virtual surgical planning by comparing planned and achieved cephalometric angles. Materials and Methods This retrospective cohort study included 53 patients with dentofacial deformities who underwent bilateral sagittal split osteotomy with (n = 29) or without Le Fort I osteotomy (n = 24). The data set comprised preoperative computed tomography scans of the skull and pre- and postoperative lateral cephalometric radiographs. Initially, two- and three-dimensional preoperative cephalometric analyses were compared to quantify measurement errors. Subsequently, angular parameters planned during three-dimensional virtual surgical planning were compared with those obtained postoperatively via two-dimensional cephalometric analysis. Clinical relevance was defined as a mean deviation greater than 2°. Results Prior to surgical intervention, no significant angular deviations were identified. Postoperatively, five out of seven angular parameters showed mean deviations statistically significant within the predefined threshold (p < 0.05). For MnP-NS and MxP-MnP, mean deviations exceeding 2° were shown (p > 0.05). Conclusions No statistically significant differences were observed between two-dimensional and three-dimensional cephalometric assessments. Planned and clinically achieved angular parameters matched to a high degree for maxillary movements, while sufficient accuracy for vertical repositioning of the mandible could not be demonstrated. Clinical Relevance: Virtual surgical planning shows sufficient accuracy for maxillary positioning. For unbiased postoperative evaluation of mandibular positioning, lateral cephalometric radiographs should be obtained after complete remission of swelling and represent a cost-effective, low-radiation alternative to three-dimensional imaging for sagittal and vertical assessment.