Face transplantation for massive mandibular defects: considerations for allograft design and surgical planning

Abstract

Modern face transplant techniques have advanced to allow for the transfer of vascularized skeletal components in addition to overlying soft tissue. This represents significant opportunity for individuals with mandibular defects that are not amenable to traditional reconstruction. Care must be taken when planning and executing transplants with these complex grafts, as satisfactory functional and aesthetic outcomes rely on achieving proper spatial relationships between the mandible, skull base, and midface. Which donor skeletal elements are included in the allograft and how they are harvested are important considerations in this planning and are associated with controversy. To optimize outcomes in the reconstruction of single-jaw defects, some advocate for transplantation of only the affected jaw while others support bimaxillary transplantation. Clinical evidence in this debate is not conclusive at this time. In current practice, including donor dentoalveolar anatomy by utilizing a bilateral sagittal split osteotomy of the mandible is favored to optimize outcomes such as dental occlusion. It has been suggested that harvesting the mandible at the level of the condyle or even the temporal bone may also be possible and may improve temporomandibular joint-related outcomes. Despite encouraging preclinical evidence, these strategies remain controversial. After allograft design, successful mandibular reconstruction with face transplantation relies on surgical precision in the donor and recipient procedures. Computerized surgical planning, computer-aided design and manufacturing, and intraoperative navigation are technologies currently in use to mitigate operative complexity. Results in both cadaveric and clinical face transplantations suggest these technologies are reliable and beneficial, although some room for improvement remains.