Abstract: Objective · To introduce the design and manufacture of the custom-made temporomandibular joint (TMJ)-mandible prosthesis and evaluate its safety, effectiveness and accuracy in clinical application. Methods · Six patients with the TMJ osteoarthrosis were included in this study. The maxillofacial CT data for all the patients were obtained and transferred into the Mimics 18.0 software preoperatively. The custom-made TMJ-mandible prosthesis was designed based on the anatomy and movement of the TMJ, and fabricated by 3D printing and 5-axis milling technologies. The TMJ-mandible lesion has been removed completely from modified preauricular, post and sub mandibular incisions. The combined prosthesis has been implanted after complete lesion resection. Then, the iliac or fibular bone has been grafted and fixed in the medial side of the prosthesis. The clinical follow-up and radiography examinations were taken after surgery to assess the safety and effectiveness for using. The postoperative CT scan was used to measure the implanted deviation compared with the preoperative design. Results · During the operations, all prosthesis were positioned smoothly, easily adapted to the bone surfaces, and fixed excellently. There were no prosthesis displacement, loosening, and fracture in X-ray postoperatively. The pain, diet, mandibular movement and open mouth had significant improvements after 19 months' follow-up. The merged postoperative CT scans indicated that the mean differences between predesigned positions of prosthesis and postoperative implantation sites were (0.891±0.127) mm for the fossa component and (1.240±0.246) mm for the mandibular component. The total average error was (1.122±0.198) mm. Conclusion · The TMJ-mandible combined prosthesis is safe, effective, and precise for the clinical application.

Key words: temporomandibular joint, mandible, combined prosthesis, custom-made, 3D printing