Precision of orthognathic digital plan transfer using patient-specific cutting guides and osteosynthesis versus mixed analogue-digitally planned surgery: a randomized controlled clinical trial

Over the last decade, the accuracy of three-dimensional computer-assisted orthognathic surgery has been investigated extensively. The absence of high-quality controlled trials, limited number of studies overall, and methodological flaws have hindered its use in general clinical practice. The aim of this study was to assess the accuracy of computer-assisted orthognathic surgery compared to the classic occlusal wafers. Eighteen patients were randomly allocated to two groups: CAD/CAM splints and patient-specific osteosynthesis were used for maxillary positioning in group 1; occlusal wafers fabricated on a semi-adjustable articulator were used in group 2. Patients were assessed for linear and angular deviations of maxillary position from the virtual plan using cone beam computed tomography scans. The CAD/CAM group showed mean deviations of 0.26 mm vertically, 0.17 mm anteroposteriorly, and 0.07 mm mediolaterally, while the classic wafer group showed mean deviations of 1.45 mm vertically, 1.31 mm anteroposteriorly, and 0.71 mm mediolaterally. Statistical analysis showed that the proposed workflow provided a significantly more accurate plan transfer compared to classic occlusal wafers. Despite the statistical significance, the clinical significance was less appreciated. However, this new technology facilitated cases with skeletal asymmetry, reduced operating times, and allowed a trainee surgeon to perform the procedure with great accuracy and minimal time. The main limitation was the high cost.