Macaca mulatta is a good model for human mandibular fixation research

Area of Science:

• Biomechanics
• Orthopedic Surgery
• Biomedical Engineering

Background:

• Optimal fixation for mandibular angle fractures remains debated.
• Previous studies suggest less rigid fixation and contralateral chewing create abnormal strain.
• Species-specific morphological differences may impact translational research.

Purpose of the Study:

• To compare the biomechanical behavior of human and macaque mandibles using finite-element models.
• To evaluate fixation techniques for mandibular angle fractures under physiological loading.
• To validate the rhesus macaque as an animal model for mandibular fixation research.

Main Methods:

• Development of realistically loaded finite-element models for human and macaque mandibles.
• Simulation of pre- and post-fracture conditions with single-plate (Champy) and biplanar fixation.
• Analysis of global bone strains, moments, and interfragmentary strains under various chewing conditions.

Main Results:

• Human and macaque mandibles exhibited similar deformation and strain patterns.
• Biplanar fixation more closely replicated healthy mandibular bone strains and moments compared to Champy fixation.
• Contralateral chewing significantly increased strain deviations, particularly with Champy fixation.

Conclusions:

• Rigid biplanar fixation is biomechanically superior to single-plate fixation for isolated mandibular angle fractures.
• Rhesus macaques demonstrate high congruence with human biomechanics, validating their use in mandibular fixation studies.
• Findings support the clinical adoption of rigid biplanar fixation for improved patient outcomes.