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Page 6 of 8 Palmer et al. Plast Aesthet Res 2020;7:2 I http://dx.doi.org/10.20517/2347-9264.2019.34

was constructed from a representation of the recipient after virtual osteotomy; in other words, the model
[8]
represented the recipient’s facial skeleton prior to graft inset . During the donor harvest, the proposed
[8]
allograft was aligned to this stereolithographic model before severing the graft’s supporting vasculature .
This technique allowed the surgical team to optimize the fit and adapt surgical hardware in advance of
[8]
ischemia time . The team demonstrated no significant difference in cephalometric variables including
[8]
occlusal plane angles between the virtual surgical plans and the postoperative results . Postoperative
[9]
[8]
occlusion was also successfully achieved . Dorafshar et al. demonstrated similarly encouraging results in
their study of five bimaxillary cadaver transplants conducted with donor osteotomies under intraoperative
navigation and recipient osteotomies facilitated by custom-manufactured cutting guides. This team found
that the postoperative results closely mirrored the computer-designed surgical plan in five of the six axes of
[9]
movement with significant differences only appearing in lateral translation .

Fidelity to the virtual surgical plan has also been demonstrated in several clinical face transplantations.
[28]
Sosin et al. successfully performed a facial transplantation including the genial segment of the
mandible with CSP and CAD/CAM and noted postoperative results in close agreement with their virtual
[18]
plan. Dorafshar et al. utilized cutting guides, intraoperative navigation, and donor alignment to a
stereolithographic model of the recipient in their double-jaw transplantation with high fidelity to the virtual
[9]
plan and postoperative maintenance of occlusion. Dorafshar et al. also followed their five cadaveric
transplants with a clinical transplant employing the same protocol and noted similar postoperative results
[4]
between the two groups. More recently, Ramly et al. reported two bimaxillary transplants facilitated by
CSP, CAD/CAM, and intraoperative navigation that both resulted in adherence to the virtual surgical plan
and class I occlusion following transplantation. Together, these results support the feasibility of conducting
face transplantation with computer-aided strategies and achieving reliable postoperative results. As these
surgical plans are tailored to the reconstructive goals of each recipient-donor pair, it follows that technology
[7]
enabling the accurate reproduction of these plans should optimize patient outcomes .
While evidence to date supports the role of CSP and other computer-based strategies in maximizing
operative efficiency and optimizing postoperative face transplantation results, there remains room for
[9]
[5]
improvement . The evidence provided by Dorafshar et al. serves as a reminder that a degree of infidelity
between the virtual plan and the postoperative results exists. These authors suggest that fidelity to the
virtual plan may improve as teams become more comfortable with CSP strategies but that the surgeon
will likely still be required to make decisions based on intraoperative observations, particularly in cases of
[9]
challenging anatomy . It is also important to understand that while encouraging, fidelity to a virtual plan
does not necessarily result in enduring spatial relationships. Current CSP technology is not equipped to
accurately account for the influence of recipient musculature on postoperative allograft positioning [4,5,11] . In
[4]
the two clinical bimaxillary transplants reported by Ramly et al. , both patients developed malocclusion
during their recoveries despite the class I occlusion observed after transplantation. One of these patients
[4]
also subsequently required mandibular coronoidectomy to improve mandibular mobility . Improved
CSP software that can predict dynamic bone-to-bone relationships in the context of postoperative muscle
[4]
recovery may help to improve long-term occlusive and TMJ outcomes .

CONCLUSION
Face transplantation techniques have evolved to allow for the inclusion of vascularized bone in the
donor allograft. For individuals with large, complex facial defects involving the mandible, these grafts
represent a valid and important option for reconstruction when other strategies fail. Thoughtful allograft
design, thorough surgical planning, and precise execution of these procedures are necessary to ensure
proper postoperative relationships between the mandible and the maxilla as well as the mandible and
the skull base. By establishing proper relationships between these skeletal elements, surgeons can restore
the aesthetics and functionalities lost with massive mandibular injury. Transplantation of the TMJ and