The aesthetic and functional outcomes surrounding Le Fort–based, face-jaw-teeth transplantation have been suboptimal, often leading to posttransplant class II/III skeletal profiles, palatal defects, and “hybrid malocclusion.” Therefore, a novel technology—real-time cephalometry—was developed to provide the surgical team instantaneous, intraoperative knowledge of three-dimensional dentoskeletal parameters.
Mock face-jaw-teeth transplantation operations were performed on plastic and cadaveric human donor/recipient pairs (n = 2). Preoperatively, cephalometric landmarks were identified on donor/recipient skeletons using segmented computed tomographic scans. The computer-assisted planning and execution workstation tracked the position of the donor face-jaw-teeth segment in real time during the placement/inset onto recipient, reporting pertinent hybrid cephalometric parameters from any movement of donor tissue. The intraoperative data measured through real-time cephalometry were compared to posttransplant measurements for accuracy assessment. In addition, posttransplant cephalometric relationships were compared to planned outcomes to determine face-jaw-teeth transplantation success.
Compared with postoperative data, the real-time cephalometry–calculated intraoperative measurement errors were 1.37 ± 1.11 mm and 0.45 ± 0.28 degrees for the plastic skull and 2.99 ± 2.24 mm and 2.63 ± 1.33 degrees for the human cadaver experiments. These results were comparable to the posttransplant relations to planned outcome (human cadaver experiment, 1.39 ± 1.81 mm and 2.18 ± 1.88 degrees; plastic skull experiment, 1.06 ± 0.63 mm and 0.53 ± 0.39 degrees).
Based on this preliminary testing, real-time cephalometry may be a valuable adjunct for adjusting and measuring “hybrid occlusion” in face-jaw-teeth transplantation and other orthognathic surgical procedures.
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Laurel, Baltimore, and Bethesda, Md.; and Boston, Mass.
From the Johns Hopkins University Applied Physics Laboratory; the Department of Mechanical Engineering, Johns Hopkins University; the Department of Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine; Craniofacial Imaging, Naval Postgraduate Dental School, 3D Medical Center, and the Department of Ear, Nose, and Throat–Head and Neck Surgery, Walter Reed National Medical Center; and Harvard School of Dental Medicine/Harvard Medical School.
Received for publication October 29, 2014; accepted February 2, 2015.
The first two authors should be considered co–first authors.
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Disclosure: Dr. Gordon is a consultant for Stryker CMF. All other authors have no conflicts of interest to report. This study was made possible, in part, by the Johns Hopkins Institute for Clinical and Translational Research, which is funded in part by the National Center for Advancing Translational Sciences, a component of the National Institutes of Health, and National Institutes of Health Roadmap for Medical Research. Its contents are solely the responsibility of the authors and do not necessarily represent the official view of the Johns Hopkins Institute for Clinical and Translational Research, the National Center for Advancing Translational Sciences, or National Institutes of Health (National Center for Advancing Translational Sciences grant UL1TR000424-06).
Chad R. Gordon, D.O., Department of Plastic and Reconstructive Surgery, Johns Hopkins University School of Medicine, JHOC, no. 8152, 601 North Caroline Street, Baltimore, Md. 21287, email@example.com