Facial transplantation has ushered in a new era of craniofacial surgery but already surgeons are pushing the boundaries of what can be achieved.
Most candidates for facial transplant have loss of soft tissues only, like skin, muscle, blood vessels, and nerves. Although still a rare and relatively new procedure, facial transplantation now offers a reconstructive option for patients with severe facial deficits and so doctors are creating a roadmap for work on patients with extensive facial defects, including loss of the normal bone and soft tissue landmarks. 'Reverse craniofacial planning' approach can restore normal facial relationships.
In the traditional craniofacial procedure, the surgeon carefully plans and designs "bone movements that will translate into a desired change of the attached soft tissues." But in facial transplantation, the situation is essentially reversed: the degree of injury and the subsequent transplantation of facial soft tissues dictate the "osteosynthesis" of the craniofacial skeleton. A new paper describes a simple but practical technique for surgical planning to promote proper positioning of the facial transplant. The technique applies "normative" data on facial landmarks and relationships and then transposes them onto the recipient.
Understanding the relationships of facial structure allows surgeons to compensate for missing bony or soft tissue landmarks. The authors provide a straightforward approach to establishing a plane of reference, allowing the facial transplant to be positioned in a proper relationship with the skull base and occlusal plane (teeth and lower face).
Optimal positioning of the facial transplant is essential not only to achieve the most normal-appearing result, but also to maximize function—particularly in eating and breathing. Dr. Caterson and colleagues emphasize that "proper positioning of the hard tissues of the allograft is the fundamental starting point for functional and aesthetic restoration." As long as the bony structure is right, any cosmetic soft tissue problems that remain after surgery are relatively easy to correct.
The authors believe that such craniofacial principles are likely to become an increasingly important consideration, "especially with the trend toward full face transplantation." In early experience, donor selection for face transplantation has focused mainly on immunological factors, similar to those used in organ transplantation.
In the future, transplant teams may become more sophisticated in donor selection, including assessment of the degree of "craniofacial match" between donors and recipients. In the meantime, the authors conclude, "[C]areful attention to the soft tissue relationships with the skeletal anatomy requires that face transplantation include 'reverse craniofacial planning' to optimize the form and function of the recipient's new face."
Published in The Journal of Craniofacial Surgery.
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