title: Computer-assisted, Le Fort-based, face-jaw-teeth transplantation: a pilot study on system feasiblity and translational assessment.
abstract: OBJECTIVE
  Le Fort-based face-jaw-teeth transplantation (FJTT) attempts to marry bone and teeth geometry of size-mismatched face-jaw-teeth segments to restore function and form due to severe mid-facial trauma. Recent development of a computer-assisted planning and execution (CAPE) system for Le Fort-based FJTT in a pre-clinical swine model offers preoperative planning, and intraoperative navigation. This paper addresses the translation of the CAPE system to human anatomy and presents accuracy results.
  
  
  METHODS
  Single-jaw, Le Fort-based FJTTs were performed on plastic models, one swine and one human, and on a human cadaver. Preoperative planning defined the goal placement of the donor's Le Fort-based FJTT segment on the recipient. Patient-specific navigated cutting guides helped achieve planned osteotomies. Intraoperative cutting guide and donor fragment placement were compared with postoperative computed tomography (CT) data and the preoperative plan.
  
  
  RESULTS
  Intraoperative measurement error with respect to postoperative CT was less than 1.25 mm for both mock transplants and 3.59 mm for the human cadaver scenario. Donor fragment placement (as compared to the planned position) was less accurate for the human model test case (2.91 mm) compared with the swine test (2.25 mm) and human cadaver (2.26 mm).
  
  
  CONCLUSIONS
  The results indicate the viability of the CAPE system for assisting with Le Fort-based FJTT and demonstrate the potential in human surgery. This system offers a new path forward to achieving improved outcomes in Le Fort-based FJTT and can be modified to assist with a variety of other surgeries involving the head, neck, face, jaws and teeth.
authors.affiliation: Research and Exploratory Development Department, Johns Hopkins University Applied Physics Laboratory, Laurel, MD, USA.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Murphy
authors.forename: Chad R
authors.initials: CR
authors.lastname: Gordon
authors.forename: Ehsan
authors.initials: E
authors.lastname: Basafa
authors.forename: Peter
authors.initials: P
authors.lastname: Liacouras
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Grant
authors.forename: Mehran
authors.initials: M
authors.lastname: Armand
mesh_terms: D000818:Animals; D002508:Cephalometry / Q000379:methods; D054445:Facial Transplantation / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007568:Jaw / Q000637:transplantation*; D010027:Osteotomy / Q000379:methods; D010347:Patient Care Planning; D010865:Pilot Projects; D025321:Surgery, Computer-Assisted / Q000379:methods*; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods; D014070:Tooth / Q000637:transplantation*