Optimal placement of fixation system for scaffold-based mandibular reconstruction

Area of Science:

• Biomaterials Science
• Biomechanics
• Orthopedic Surgery

Background:

• Bone tissue engineering faces challenges in creating optimal biomechanical conditions for scaffold regeneration, especially before osseointegration.
• Mandibular reconstruction of large segmental defects requires careful consideration of fixation system placement to influence mechanical stimuli and structural integrity.

Purpose of the Study:

• To determine the optimal height and angle for a titanium fixation plate in mandibular reconstruction using a bioceramic scaffold.
• To enhance tissue ingrowth, structural strength, and structural stiffness of the scaffold-host bone construct.

Main Methods:

• Utilized CT-based finite element (FE) modeling to simulate biomechanical responses under varying fixation plate positions.
• Employed surrogate modeling to generate polynomial functions for biomechanical responses.
• Applied multi-objective particle swarm optimization to identify Pareto-optimal solutions for competing design criteria.

Main Results:

• Fixation plate height significantly influences the volume of scaffold experiencing mechanical stimulus for bone apposition.
• Mechanical stimulus ingress is observed from the buccal side towards the scaffold's center, concentrated around screw regions.
• Optimal placement involves positioning the fixation system along the upper mandibular boundary with slight clockwise rotation.

Conclusions:

• The developed methodology provides a decision aid for optimizing surgical planning in mandibular reconstruction.
• Optimal fixation plate positioning is crucial for maximizing bone regeneration and ensuring construct stability.
• Balancing competing biomechanical objectives through multi-objective optimization leads to superior outcomes in bone tissue engineering.