Accurate reconstruction of discontinuous mandible using a reverse engineering/computer-aided design/rapid prototyping technique: a preliminary clinical study.
OBJECTIVE
To improve the reconstructive surgical outcome of a discontinuous mandibular defect, we used reverse engineering (RE), computer-aided design (CAD), and rapid prototyping (RP) technique to fabricate customized mandibular trays to precisely restore the mandibular defects. Autogenous bone grafting was also used to restore the bony continuity for occlusion rehabilitation.


METHODS
Six patients who had undergone block resection of the mandible underwent reconstruction using a custom titanium tray combining autogenous iliac grafts. The custom titanium tray was made using a RE/CAD/RP technique. A virtual 3-dimensional model was obtained by spiral computed tomography scanning. The opposite side of the mandible was mirrored to cover the defect area to restore excellent facial symmetry. A bone grafting tray was designed from the mirrored image and manufactured using RP processing and casting. The mandibular defects were restored using the trays in combination of autologous iliac grafting. An implant denture was made for 1 of the 6 patients at 24 weeks postoperatively for occlusion rehabilitation.


RESULTS
The trays fabricated using this technique fit well in all 6 patients. The reconstructive procedures were easy and time saving. Satisfactory facial symmetry was restored. No severe complications occurred in the 5 patients without occlusion rehabilitation during a mean 50-month follow-up period. The reconstruction in the patient with occlusion lasted for only 1 year and failed eventually because of bone resorption and infection.


CONCLUSIONS
Mandibular reconstruction was facilitated using the RE/CAD/RP technique. Satisfactory esthetic results were achieved. However, the rigidity of the cast tray could cause severe stress shielding to the grafts, which could lead to disuse atrophy. Therefore, some modification is needed for functional reconstruction.
Zhou
Li-bin
LB
Department of Oral and Maxillofacial Surgery, School of Stomatology, Fourth Military Medical University, Shaanxi, People's Republic of China.
Shang
Hong-tao
HT
He
Li-sheng
LS
Bo
Bin
B
Liu
Gui-cai
GC
Liu
Yan-pu
YP
Zhao
Jin-long
JL
D000328:Adult; D016025:Bone Transplantation; D017076:Computer-Aided Design; D019094:Dental Prosthesis, Implant-Supported / Q000009:adverse effects; D003799:Dental Stress Analysis; D003832:Denture, Partial, Removable; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D008336:Mandibular Diseases / Q000534:rehabilitation; D008339:Mandibular Neoplasms / Q000534:rehabilitation; D008341:Mandibular Prosthesis; D019930:Mandibular Prosthesis Implantation / Q000379:methods; D008953:Models, Anatomic; D019647:Oral Surgical Procedures / Q000295:instrumentation / Q000379:methods*; D011474:Prosthesis Design; D019651:Plastic Surgery Procedures / Q000295:instrumentation / Q000379:methods*; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D014025:Titanium; D036542:Tomography, Spiral Computed; D055815:Young Adult
D014025:Titanium