Precision of the fully digital 3D treatment plan

Virtual 3D planning of orthognathic surgery has become the gold standard of modern orthognathic surgery, but questions about precision remain crucial. The objective of the study was to evaluate precision of the digital 3D orthognathic surgery plan for bimaxillary surgery compared to the actual surgical outcome in all three dimensions. 30 patients were involved in the present study (11 male; 19 females; average age 23.7 years). 24 patients were Class III and 6 were Class II. The preoperative and postoperative CBCT after bimaxilary surgery of each patient was superimposed. Eleven dental and skeletal points were used for comparison between the real and digital outcome in all three planes. In our study, average measurement values for all points were less than 2 mm. After further scrutiny of cases with larger discrepancies it was discovered that those cases were planned without “piggy-back” final occlusion definition method. In addition, these cases had pronounced facial asymmetry and occlusal plane canting.The data obtained in this study show that the surgical plan for maxillary movement is more predictable and precise when compared to the mandibular one in the sagittal and vertical plane. Method of surgical outcome precision analysis presented in this paper provides better insight about discrepancies that may arise from virtual plan to surgical outcome. The results indicate that 3D digital planning of orthodontic surgery, if transferred appropriately, is an accurate assessment of the surgical outcome and there is no clinically significant difference between the planned and actual position. More improvements and innovations in virtual planning software could further improve surgical outcome precision.