Virtual bending of mandibular reconstruction plates using a computer-aided design.
OBJECTIVE
The purpose of this study was to investigate the possibility of virtually designing and manufacturing a template for reconstruction plate bending, to be used during treatment of congenital or acquired bony entities. The outcome was compared with plates bent by the freehand approach in a stereolithographic skull model.


METHODS
From a computed tomography examination, a polygon skull was created and the corresponding stereolithographic model retrieved. A polygon mesh of a Compact UniLock 2.4-mm plate was obtained from Synthes (Bettlach, Switzerland). The polygon plate was bent virtually around the mandible and rendered in all 3 dimensions, and a template was created. Five 10-hole plates were bent using this template, and five 10-hole plates were bent using a stereolithographic model as the template. The 2 groups were compared using the Wilcoxon signed rank test. P values less than .001 was considered to be statistically significant.


RESULTS
No statistical difference was seen between the 2 methods. The median discrepancy between the 2 groups was 0.1 mm.


CONCLUSIONS
Within the constraints of this investigation, by use of a virtually produced template based on a virtually planned reconstruction, it is possible to bend a reconstruction plate with the same degree of accuracy as that of the traditional freehand approach.
Dérand
Per
P
Consultant, Department of Surgical Sciences, Oral and Maxillofacial Surgery, Medical Faculty, Uppsala University, Uppsala, Sweden. per.derand@adamomail.se
Hirsch
Jan-Michael
JM
D001860:Bone Plates; D017076:Computer-Aided Design; D006801:Humans; D021621:Imaging, Three-Dimensional; D008334:Mandible / Q000601:surgery*; D010347:Patient Care Planning; D010865:Pilot Projects; D011474:Prosthesis Design; D011873:Radiology Information Systems; D019651:Plastic Surgery Procedures / Q000295:instrumentation*; D013499:Surface Properties; D025321:Surgery, Computer-Assisted; D014057:Tomography, X-Ray Computed; D014584:User-Computer Interface