Biomechanical In Vitro Study on the Stability of Patient-Specific CAD/CAM Mandibular Reconstruction Plates: A Comparison Between Selective Laser Melted, Milled, and Hand-Bent Plates

Abstract

Study Design: An experimental in vitro study. Objective: Plate fractures are a recurrent problem in alloplastic mandibular reconstruction. Hypothetically it can be assumed that computer-aided design (CAD)/computer-aided manufacturing (CAM) reconstruction plates have a higher stability than conventional hand-bent plates. The aim of the study was to compare additive and subtractive fabricated CAD/CAM mandibular reconstruction plates as well as conventional plates with regard to their biomechanical properties. Methods: In a chewing simulator, plates of 2 conventional locking plate systems and 2 CAD/CAM-fabricated plate systems were compared. The plates were loaded in a fatigue test. The maximum number of cycles until plate fracture and the plate stiffness were compared. Results: While all conventional plates fractured at a maximum load between 150 and 210 N (Newton) after a number of cycles between 40 000 and 643 000, none of the CAD/CAM plates broke despite a nearly doubled load of 330 N and 2 million cycles. Both CAD/CAM systems proved to be significantly superior to the hand-bent plates. There was no difference between the 2 CAD/CAM systems. Conclusions: Concerning the risk of plate fracture, patient-specific CAD/CAM reconstruction plates appear to have a significant advantage over conventional hand-bent plates in alloplastic mandibular reconstruction.

The Precision of Different Types of Plates Fabricated With a Computer-Aided Design and Manufacturing System in Mandibular Reconstruction With Fibular-Free Flaps

“…First, the sample size was relatively small among the published literature. 17,27,28 Second, there were differences between the surgical simulation in bone models and actual reconstructed mandible in vivo, such as the screw direction errors, as detected in this study. In this case, we needed to consider the potential errors in the bone model itself.…”

“…In this study, a few limitations should be considered when interpreting the experimental results. First, the sample size was relatively small among the published literature 17,27,28. Second, there were differences between the surgical simulation in bone models and actual reconstructed mandible in vivo , such as the screw direction errors, as detected in this study.…”

“…The patient-specific plate has not only great accuracy but also durability to force load. There was an in vitro study by Kasper et al,17 which reported that patient-specific plate seemed to benefit from manually bending reconstruction plate in terms of durability against physiological force loading. These results suggested the benefit of using patient-specific plate over manually bending reconstruction plate.…”

“…The first group used CAD/CAM combined with patient-specific plate. [15][16][17] The second group used CAD/CAM combined with manually bending reconstruction plate. 4,5,[18][19][20][21][22][23][24][25][26] The last group used CAD/CAM combined with miniplate.…”

“…According to published literature, the subjects were separated into 3 categories by using different plate fixation methods. The first group used CAD/CAM combined with patient-specific plate 15–17. The second group used CAD/CAM combined with manually bending reconstruction plate 4,5,18–26.…”