Biomechanical Evaluation of a Novel Stepped Bone Reconstruction Structure for the Mandible Under Traumatic Impact Loading.

OBJECTIVES

In daily life, following mandibular reconstruction surgery, accidental events such as falls and impacts may lead to fracture, displacement, or failure of the reconstructed site. This study investigates the biomechanical behavior of a Stepped Bone Reconstruction Structure (SBRS) when subjected to transient traumatic loads postoperatively.

METHODS

On the basis of CT scans, an SBRS model was established. Two magnitudes of impact loads were simulated at 5 different locations: frontal symphyseal, left parasymphyseal, right parasymphyseal, left mandibular angle, and right mandibular angle. The stress distribution characteristics of the model were thereby obtained.

RESULTS

The maximum stresses in the mandible, fibula, and titanium screws were consistently observed at the screw holes and the interface between the screws and the healing surface. Under a transient impact load of 1000 N, the maximum stresses for the mandible, fibula, and titanium screws were 68.75, 90.37, and 185.0 MPa, respectively. When subjected to a transient impact load of 2000 N, the corresponding maximum stresses increased to 128.5, 133.7, and 370.6 MPa.

CONCLUSION

On the basis of the finite element analysis, it was found that in the SBRS, under transient impact loading, the maximum stress is primarily concentrated in the regions of the screw holes and the interface between the screws and the healing surface. Furthermore, the stress magnitude increased correspondingly with higher impact loads.