The three-dimensional cancellous bone architecture of the human mandibularcondyle

in the present study, we tested the hypothesis that the cancellous bone of the mandibular condyle is inhomogeneous and anisotropic. For this purpose, 11 mandibular condyles from embalmed human cadavers were scanned in a micro -CT system. Within each condyle, 9 volumes of interest were selected from d ifferent mediolateral and superoinferior regions. Several bone parameters w ere calculated to describe the morphology. It appeared that the cancellous bone of the condyle could be approximated by parallel plates. These plates were almost vertically oriented at an angle of 17 degrees relative to the s agittal plane, i.e., perpendicular to the condylar axis. In the superior re gions of the condyle, the cancellous bone had the largest bone volume fract ion (0.19), associated with the thickest trabeculae (0.11 mm), and the high est trabecular number (1.72 mm(-1)). The lowest bone volume fraction (0.15) was found more inferiorly. The degree of anisotropy increased from superio r to inferior across the condyle. No mediolateral differences in bone morph ology were found, but superiorly central regions contained more bone than p eripheral regions. The plate-like trabeculae could indicate that the condyl e is optimally adapted to sustain loads from all directions in a plane perp endicular to the condylar axis. The high bone mass and lower anisotropy in the superior regions could enable the condyle to sustain multiple load dire ctions. Toward the collum, the trabeculae are more aligned. This could poin t to stresses acting predominantly in one direction.