Mechanical significance of the trabecular microstructure of the human mandibular condyle.

The human mandibular condyle has a parasagittal plate-like trabecular structure. We tested the hypothesis that this structure reflects the mechanical loading of the condyle. We developed a finite element model of the condyle to analyze the strains occurring during static compressive loading. The principal strains in the trabecular bone were primarily oriented in the sagittal plane. The first component was compressive and oriented supero-inferiorly. The second component was negligibly small and oriented medio-laterally. The third component was tensile, oriented antero-posteriorly, and almost equal to the compressive strain. This tensile strain was caused by antero-posterior bulging of the cortex. This means that the trabecular structure is also subjected to significant tensile forces. The orientation of the parasagittal strains followed the direction of the applied load. It was concluded that the trabecular structure of the mandibular condyle is optimal in resisting the compressive and tensile strains to which it is subjected.