Considerations for Temporomandibular Joint Procurement in Vascularized Composite Allotransplantation

Abstract

Methods for harvest of the temporomandibular joint (TMJ) for transplantation may involve several anatomic levels. The authors aim to assess the feasibility and identify challenges with 2 such methods, resuspending the donor condyles from the recipient glenoid fossae and en bloc harvest of the joint and surrounding temporal bone with plate-fixation to the recipient skull base. Two mock face transplantations were carried out using 4 fresh cadavers. Computed tomography imaging was obtained before and after the procedures to assess the technical success of each method. Both techniques were technically successful, allowing for full passive jaw range of motion following graft transfer and appropriate condyle positioning as assessed by computed tomography. En bloc TMJ harvest allowed for transfer of the entire joint without violating its capsule or altering its biomechanics. The authors found this technique better able to avoid issues with size mismatch between the donor mandible and recipient skull base width. When no such mismatch exists, graft harvest at the level of the mandibular condyle is technically easier and less time consuming. Although both methods of TMJ harvest are technically feasible with acceptable immediate postoperative jaw position and range of motion, the en bloc technique allows for more natural jaw function with less risk of postoperative joint immobility by preserving the joint capsule and its ligamentous support.

The 2020 Facial Transplantation Update: A 15-Year Compendium

“…Three methods of TMJ harvest have been explored in cadaveric simulations, with full passive mandibular range of motion obtained posttransplant. 65 , 66 However, important clinical considerations for TMJ-containing FT remain largely unaddressed, including TMJ dynamics after FT, occlusion, and long-term development of TMJ-related complications.…”

Maxillofacial Bony Considerations in Facial Transplantation

“…Research is ongoing, and studies are currently evaluating different options for managing the TMJ, from transfer of the condyle and suture suspension to transfer of the entire joint capsule and part of the temporal bone. 16 Often, precontoured custom plates are not necessary, and short plates spanning each osteotomy site can be efficiently and effectively fashioned intraoperatively. That said, preoperative planning is an important part of successful facial transplantation, and there are numerous technologies available today that can improve the chances for a successful operation and successful long-term outcome.…”