Variation in stress distribution modified by mandibular material property: a 3D finite element analysis

Area of Science:

• Biomechanical Engineering
• Oral and Maxillofacial Surgery
• Computational Mechanics

Background:

• Temporomandibular joint disorder (TMD) is a prevalent oral and maxillofacial condition.
• The finite element method (FEM) is extensively utilized in TMD research.
• Accurate material assignment in FEM is critical for reliable TMD analysis, yet previous methods lack comprehensive assessment.

Purpose of the Study:

• To evaluate the impact of different mandibular material modeling approaches on FEM results for TMD.
• To assess how variations in tooth elastic modulus affect stress distribution in TMD models.
• To compare the efficacy of uniform, semi-uniform, and non-uniform modeling techniques.

Main Methods:

• Four mandible material modeling approaches were investigated: uniform (cortical/cancellous bone) and semi-uniform, and non-uniform (CT gray value related modulus).
• Teeth Young's modulus varied from 20 to 300 GPa.
• Ten distinct models were analyzed to compare contact pressure and force differences.

Main Results:

• Increased teeth elastic modulus amplified maximum contact pressure on alveolar bone and contact force on teeth.
• Temporomandibular joint stress showed insignificant variation with increased teeth elastic modulus.
• Maximum contact pressure location was consistent across all four modeling approaches, with insignificant differences in magnitude.

Conclusions:

• Higher tooth elastic modulus significantly concentrates stress in alveolar bone, with minimal impact on temporomandibular joint stress.
• The four mandibular models accurately predicted extreme stress regions consistent with actual damage.
• Non-uniform modeling using CT values offers a superior representation of human bone mechanical properties for TMD studies.