Application of rapid prototyping for temporomandibular Joint reconstruction.

PURPOSE: The purpose of this study is to introduce the preliminary application of rapid prototyping (RP) for temporomandibular joint (TMJ) surgery. METHODS: 11 consecutive patients (13 joints) seeking for TMJ replacement were included in this study. All patients had previously undergone 3-dimensional computed tomography (CT) scannings (0.625mm slice thickness) of the craniofacial skeleton. The data from CT scan with DICOM format were input into an interactive Simplant CMF software (Materialise Medical, Leuven, Belgium). Preoperative planning included segmentation and osteotomies. The movements of the jaw hones was simulated using the Simplant CMF. The affected mandible was reconstructed, based on the contralateral side. Then the titanium plate was shaped on the reconstructed model before operation. The bone graft was transplanted by the shaped titanium plate during the operation to reconstruct the TMJ. 24 patients receiving traditional surgery were used as control. The operation time of the two group were analyzed with SPSS 13.0 software package for Student's t test. The data of CT scan of the experimental group before and after operation were compared by paired t test. RESULTS: All the incisions were healed primarily without any complications. All patients were satisfied with the operation, due to their symmetrical face and good occlusion. The postoperative MRI confirmed the position of transplanted costchondral cartilage in the glenoid fossa. Group t test showed that the operation time was longer in control group (7.09h) than that in RP group (5.67h). Three parameters (condyle-incisor, CI; condyle-mental foramen, CM; condyle-angle, CA) from the postoperative CT scan were analyzed by paired t test, and there was no significant difference between the two sides. CONCLUSION: Rapid prototyping technology provides an advanced method for TMJ reconstruction, which can make the TMJ reconstruction more accurate and symmetrical, improve the mandibular function and consequently enhance the reconstructive effect. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality (Grant No.08DZ2271100), Shanghai Leading Academic Discipline Project (Grant No.S30206), Research Fund of Shanghai Municipal Bureau of Health (Grant No.2008 160), Research Fund of Ph.D. Programs of Shanghai Jiao Tong University School of Medicine (Grant No.BXJ0926), and Research Fund of Medicine and Engineering of Shanghai Jiao Tong University (Grant No.YG2009MS 42). [ABSTRACT FROM AUTHOR]