title: Computer-assisted design and rapid prototype modeling in microvascular mandible reconstruction.
abstract: OBJECTIVE
  To evaluate the use of computer-assisted design and rapid prototype modeling to improve the speed and accuracy of mandibular reconstruction.
  
  
  METHODS
  Case-control study.
  
  
  METHODS
  Between 2005 and 2011, 38 subjects underwent fibula free flap mandibular reconstruction using computer-assisted design and rapid prototype modeling. Titanium plates were prebent using the models prior to surgery. Direct plate bending on the native mandible to accurately restore occlusion would not have been possible in 11 patients with exophytic tumors, nine patients with pathologic fractures, and 10 patients with a prior segmental mandibulectomy. Computer-generated cutting guides were utilized to facilitate fibular osteotomies.
  
  
  RESULTS
  The mean operative time for subjects was 8.8 ± 1.0 hours compared to the mean operative time defect-matched control group, for whom computer-assisted design and models were not used, of 10.5 ± 1.4 hours (P = .0006). Comparison of the preoperative and postoperative mandibles demonstrated that the mean change in position of selected bony landmarks (condyles, gonions, and gnathion) was less in the subject group than in the control group (4.11 ± 3.09 mm vs. 6.92 ± 5.64 mm, respectively; P = .001) Comparison of postoperative mandibles with preoperative virtual plans showed a mean deviation of 2.40 ± 2.06 mm from planned fibular segment lengths and 3.51 ± 2.69° from planned angles between fibular segments.
  
  
  CONCLUSIONS
  Computer-assisted design and rapid prototype modeling have the potential to increase the speed and accuracy of mandibular reconstruction. We believe these technologies are particularly useful for cases in which the original architecture of the mandible has been distorted or destroyed.
authors.affiliation: Department of Plastic Surgery, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA. mhanasono@mdanderson.org
authors.forename: Matthew M
authors.initials: MM
authors.lastname: Hanasono
authors.forename: Roman J
authors.initials: RJ
authors.lastname: Skoracki
mesh_terms: D000368:Aged; D000564:Ameloblastoma / Q000601:surgery; D001860:Bone Plates; D002294:Carcinoma, Squamous Cell / Q000601:surgery; D016022:Case-Control Studies; D017076:Computer-Aided Design; D003646:Debridement; D005260:Female; D005598:Fractures, Spontaneous / Q000601:surgery*; D058752:Free Tissue Flaps; D006258:Head and Neck Neoplasms / Q000601:surgery; D006801:Humans; D008297:Male; D008334:Mandible / Q000473:pathology / Q000601:surgery*; D008337:Mandibular Fractures / Q000601:surgery*; D008339:Mandibular Neoplasms / Q000601:surgery*; D008866:Microsurgery; D008875:Middle Aged; D010025:Osteoradionecrosis / Q000601:surgery; D012516:Osteosarcoma / Q000601:surgery; D019651:Plastic Surgery Procedures / Q000379:methods*; D000077195:Squamous Cell Carcinoma of Head and Neck