Biomechanical analysis of different osteotomy lines in mandibular angle surgery

Area of Science:

• Biomedical Engineering
• Oral and Maxillofacial Surgery
• Computational Mechanics

Background:

• Accurate material property assignment is crucial for simulating biomechanical behavior of the mandible.
• Digital surgical planning requires reliable models for predicting surgical outcomes.
• Existing methods for material parameter assignment may influence simulation accuracy.

Purpose of the Study:

• To compare the biomechanical simulation results of mandible models using two distinct material parameter assignment methods: cortical-cancellous and grayscale-based.
• To evaluate the stress and deformation patterns under simulated surgical conditions.
• To establish a methodological foundation for personalized osteotomy.

Main Methods:

• Reconstruction of three representative mandible models.
• Assignment of material parameters using both cortical-cancellous and grayscale-based methods.
• Digital surgical planning to simulate three osteotomy trajectories under centric occlusion and impact conditions.
• Comparison of resulting stresses and deformations between the two material assignment methods.

Main Results:

• The cortical-cancellous method resulted in a wider stress gradient compared to the grayscale-based method.
• The cortical-cancellous method exhibited lower peak stress, strain, and displacement than the grayscale-based method.
• Peak stresses and displacements remained within safety thresholds for both material assignment methods.

Conclusions:

• Both material assignment methods provide results within safety thresholds for simulated osteotomy.
• The cortical-cancellous method offers a potentially more conservative estimation of peak biomechanical responses.
• This study lays the groundwork for developing more accurate and personalized digital surgical planning for mandibular osteotomies.