Navigating Complexities in Surgical Orthodontic Cases Jerry English & Kurt Kasper
Computer Aided Surgical Simulation CASS
· Planning : visualisation, surgical simulation, plan
· Execution – occlusal splint, templates, drilling guide
· Outcome assessment
Create 3D model of head and neck in NHP, accuracy in soft tissues, skeletal structures and dentition
Execution in 3D planning
· Orthodontic
o Occlusal adjustments prior to surgery
· Surgical
o Collisions in maxilla / mandible: for example Le Fort 1
Digital workflow in surgical planning
· Image acquisition: e.g. CBCT
· Digital manipulation: surgical simulation
· 3D printing: Visualisation
Use of 3D printing in orthognathic treatment Jacobs 2017, Lin 2017
1. Contour model – 3D model print of bony structure to allow plate contour
2. Surgical guide for osteotomy
3. Splint – occlusal splint
4. Implants
3D printing
· Layer by layer process
· Dimensional deviation less than 0.01mm Favero 2017
· Accuracy of models (0.25mm discrepancy) only DLP within threshold Akyalcin 2021
o Clinical relevance of discrepancy requires clinical decision making
· Print height, greater print height = less dimensional deviation (100microns Vs 25 microns, 0.080mm Vs 0.065mm) Favero 2017
o Smaller layer heights = smoother does not translate to accuracy
o May not be clinical significant
· Printer orientation
o Flat Vs Perpendicular =
§ Perpendicular = efficiency in number of models within printer,
§ Perpendicular = greater layers required
· Greater dimensional deviation with perpendicular 0.17mm Vs 0.1mm flat
· Orientation and layer height effect each other
