title: Reconstruction of mandibular defects using a custom-made titanium tray in combination with autologous cancellous bone.
abstract: OBJECTIVE
  To esthetically and functionally restore a 40-mm canine mandibular discontinuity defect using a custom-made titanium bone-grafting tray packed with autologous iliac bone.
  
  
  METHODS
  Individualized titanium bone-grafting trays were made using a reverse engineering, computer-aided design, and rapid prototyping technique. A 40-mm discontinuity defect in the right mandibular body was created in 10 hybrid dogs. The defect was restored immediately using the tray that was densely packed with autologous cancellous iliac particles and covered with trimmed iliac chips. Sequential radionuclide bone imaging was performed postoperatively at 2, 4, 8, 12, and 24 weeks. The ratio of activity between the grafted mandible and the contralateral native mandible on each transaxial slice was calculated. The mean activity ratio was analyzed at each time point to evaluate the bone metabolism and reconstitution of the grafts. The subjects were sacrificed at 4, 12, and 24 weeks after grafting. The specimens were evaluated by postmortem gross dissection, biomechanical testing, 3-dimensional microcomputed tomographic scanning, and histologic examination.
  
  
  RESULTS
  All the subjects tolerated the grafting operation well. Over an observation period of 24 weeks, tray extrusion occurred in 3 of the 10 subjects. Bony continuities were reconstructed in 9 of the 10 subjects. Radionuclide bone imaging revealed that the tracer uptake increased in the grafted mandible, and the radionuclide ratio between the graft and the native mandible decreased with time. Gross evaluation, microcomputed tomographic examination, biomechanical testing, and histologic examination demonstrated corticalization of the grafts.
  
  
  CONCLUSIONS
  The use of a customized technique using reverse engineering, computer-aided design, and rapid prototyping tray containing autologous cancellous bone is a potentially powerful grafting technique for the reconstruction of mandibular discontinuity defects.
authors.affiliation: Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, People's Republic of China.
authors.forename: Libin
authors.initials: L
authors.lastname: Zhou
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zhao
authors.forename: Hongtao
authors.initials: H
authors.lastname: Shang
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Zhihong
authors.initials: Z
authors.lastname: Feng
authors.forename: Guicai
authors.initials: G
authors.lastname: Liu
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Yanpu
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000497:Alloys; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density / Q000502:physiology; D016723:Bone Remodeling / Q000502:physiology; D016025:Bone Transplantation / Q000000981:diagnostic imaging / Q000295:instrumentation* / Q000379:methods; D017076:Computer-Aided Design; D004285:Dogs; D004867:Equipment Design; D006085:Graft Survival; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D008334:Mandible / Q000000981:diagnostic imaging; D008336:Mandibular Diseases / Q000000981:diagnostic imaging / Q000601:surgery*; D010020:Osteonecrosis / Q000209:etiology; D011183:Postoperative Complications; D019651:Plastic Surgery Procedures / Q000379:methods*; D013314:Stress, Mechanical; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D036542:Tomography, Spiral Computed / Q000379:methods; D014182:Transplantation, Autologous; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D000497:Alloys; C031462:titanium alloy (TiAl6V4); D014025:Titanium