Preliminary assessment of maxillary positioning accuracy in orthognathic surgery using CAD-CAM-generated custom-made cutting guides and osteosynthesis plates. A short report

Background: Our study aims to verify the accuracy of maxillary positioning in orthognathic surgery using CAD-CAM cutting guides and custom-made osteosynthesis plates, comparing the preoperative 3D surgical plan with the final positioning determined from postoperative CT scans.Methods: This prospective monocentric study included eight patients (aged 18–30) with dentofacial deformities (six Class III and two Class II malocclusions) who underwent bimaxillary orthognathic surgery. The digital workflow integrated CT scans and intraoral digital impressions. Customized cutting guides and selective laser-melted (SLM) titanium plates were designed to transfer the 3D-VSP to the operative field. Accuracy was assessed one month postoperatively by superimposing the surgical plan onto postoperative CT scans. Surface deviations were quantified and visualized using color maps. Results: The transfer of the virtual plan was successful in all cases with no intraoperative complications. A 100% accuracy rate was achieved, defined as a three-dimensional deviation of less than 1.5 mm. The overall mean linear error was -0.24 mm (± 0.35 mm SD). Visual analysis via color maps confirmed a marked prevalence of discrepancies ≤ 1.0 mm (green zones) across all maxillary surfaces. Statistical analysis using a paired t-test showed no significant differences between the planned and achieved positions ($p > 0.05$), indicating an absence of systematic errors. Conclusions: The reported findings suggest that CAD-CAM cutting guides and custom-made osteosynthesis plates tend to improve the accuracy in the maxillary positioning. Furthermore, custom-made osteotomy guides and plates increase the predictability and security of the surgical procedure.