Evaluating the effect of different final occlusion establishing methods on outcome of three dimensional orthognathic surgical planning

Establishing accurate final occlusion is critical for successful orthognathic surgery outcomes. This study evaluated four methods for establishing final occlusion in three-dimensional orthognathic surgical planning. Twelve patients with skeletal Class III malocclusion scheduled for bimaxillary surgery were included in this retrospective comparative study. Four methods were evaluated: conventional plaster model articulation (Method 1), semi-digital approach using 3D printed models with manual articulation (Method 2), and fully digital approaches using 3Shape OrthoSystem (Method 3) and Dolphin Imaging software (Method 4). Each patient served as their own control. Two operators independently performed occlusions and measurements are performed using Geomagic Control X software, analyzing three-dimensional linear deviations and angular measurements. Clinical acceptability thresholds were <2mm for linear deviations and <2° for angular deviations. Statistical analysis included repeated measures ANOVA, Friedman test, and intraclass correlation coefficients. All methods demonstrated clinically acceptable accuracy. Method 2 showed superior performance with smallest median deviations (0.27-0.46mm). Inter-rater reliability was excellent for anterior landmarks (ICC >0.95) and good for posterior landmarks (ICC >0.89). Method 2 achieved highest clinical acceptability rates, while digital methods showed increased variability for posterior landmarks. The LL6 landmark showed significant Z-axis differences (p=0.030), with Method 2 achieving 91.7% acceptability versus 50% for Method 4. The semi-digital approach currently offers optimal balance between technological advancement and clinical reliability. While fully digital methods show promise, they require refinement before replacing approaches incorporating tactile feedback. Future integration of haptic technology and artificial intelligence may enable complete transition to digital workflows.