Technical Report of New Condyle Repositioning Method in 3D Model

Objectives: We have had experiences to use 3D resin model for oral and maxillofacial surgical treatment. In orthognathic surgery and reconstruction cases, it is difficult to reinstate a condyle position after preoperational simulation. The purpose of this study is to introduce and asses the new condyle repositioning method in 3D model preoperational simulation.
Methods: We constructed 3D image from Digital Imaging and Communication in Medicine (DICOM) file with computed tomography using Materialise Mimics^®, that converted into a stereolithographic (STL) file, and we made 3D models using a Stratasys OBJET Connex 260^®. In jaw deformity case and benign tumor case, we developed a method improved reposition after preoperational simulation. Our new method is simple to apply irregularities (two process in condyle and resection side, and two holes in glenoid fossa and normal side) in 3D models. We evaluated that the length ramus to maxillary canine before and after preoperational simulation in orthognathic surgery cases.
Results: 3D resin models were produced using rapid prototyping technology in Fab Lab TDC. The total number of models produced were 33 cases. Thirteen cases were jaw deformity, 6 cases were benign tumors, 5 cases were osteomyelitis, and 5 cases were others. In orthognathic surgery case, glenoid fossa and condyle need to accurately reposition place after preoperational simulation. After cutting lesion and bend reconstruction plate, was restored to its former state in reconstruction cases. Our new technic improved reposition accuracy by applying irregularities on glenoid fossa and cut section. In all cases, it were accorded closely with the measurement between ramus to maxillary canine before and after preoperational simulation.
Conclusions: Most clinicians were impressed with the new technic that had higher accuracy than current method. This method is easier to cut and reposition, like “LEGO BLOCK^®”, useful for practitioners and assistants.