Biomechanical evaluation of a novel hybrid reconstruction plate for mandible segmental defects: A finite element analysis and fatigue testing

Abstract

Purpose: This study develops a novel hybrid (NH) reconstruction plate that can provide load-bearing strength, secure the bone transplant at the prosthesis favored position, and also maintain the facial contour in a mandibular segmental defect. A new patient-match bending technique which uses a three-dimensional printing (3DP) stamping process is developed to increase the interfacial fit between the reconstruction plate and mandibular bone.

Materials and methods: The NH reconstruction plate was designed to produce a continuous profile with non-uniform thickness and triangular cross-screw patterns with a locking-screw feature at the plate base. Two mandible segmental defect finite element models including the NH reconstruction plate to secure a bone flap for occlusal requirement and the commercial straight (CS) reconstruction plate to secure a bone flap along the lower mandible border were generated for biomechanical fatigue testing.

Results: The simulated results showed that the maximum von Mises stresses of the reconstruction plate for CS secured model are about 4.5 times more than the NH secured model. The bone strains around the fixation screws showed that the CS secured model was meaningfully higher than that of the NH secured model and exceeded the bone limit value. No fracture of any component was found in any sample in the fatigue testing.

Conclusion: In conclusion, the newly developed NH reconstruction plate can secure the transplant position in accordance to the individual occlusal requirements without sacrificing the maintenance of facial contour. Finite element-based biomechanical evaluation demonstrates superior mechanical strength compared to commercial standard plates.

Keywords: 3D printing; Fatigue; Finite element; Reconstruction plate; Segmental defect.