Biomechanical assessment and topological optimization of embedded polygonal bone reconstruction structures

Area of Science:

• Biomaterials Engineering
• Computational Mechanics
• Oral and Maxillofacial Surgery

Background:

• Conventional mandibular reconstruction methods can lead to stress shielding, poor osteotomy site healing, and bone resorption.
• Titanium plates are often required, introducing potential complications and limitations.

Purpose of the Study:

• To introduce and evaluate an Embedded Polygonal Bone Reconstruction Structure (EPBRS) for mandibular reconstruction.
• To assess the biomechanical performance of EPBRS with fillet-based topological optimization, aiming to eliminate titanium plate dependency.

Main Methods:

• A computational model of the EPBRS was created using CT scan data.
• Four EPBRS variants with varying fillet radii (0.2-0.8 mm) were designed and simulated.
• Physiological masticatory loading was applied, and von Mises stress and peak displacements were calculated.

Main Results:

• Increasing fillet radius reduced maximum von Mises stress in the fibula graft (87.21 MPa to 37.59 MPa) and mandible (100.73 MPa to 23.9 MPa).
• Peak displacements decreased with initial fillet radius increases and remained stable.
• Stress in titanium screws remained invariant (170-185 MPa).

Conclusions:

• The EPBRS demonstrates significant biomechanical safety and reliability for mandibular reconstruction.
• Fillet optimization effectively reduces stress concentrations and enhances resistance to deformation.
• This approach offers a promising alternative to traditional methods, potentially avoiding titanium plate complications.