Biomedical Sciences, Texas A&M Health Science Center Baylor College of Dentistry, Dallas, TX
Saturday Morning, Forum Suite
Moderately correlated with elastic moduli and yield strength, bone density is a partial determinant of bone quality and can be used in behavioral assessment as an indicator of bone remodeling, tissue age, and functional adaptation. It must be determined for estimates of 3D elastic properties for finite element modeling, a numerical technique for understanding the functional behavior of skeletal organs. The bone density measurement standard is through using Archimedes principle and densitometry apparatus based on accurate scale measurements. This requires preparation of small samples and does not allow continuous cortical sampling. MicroCT is a 3D radiographic technique which is used to examine hard tissue structure and with adequate calibration, might be used for determining continuous variations in bone density. This study compares density measured by these techniques. 40 cylindrical bone specimens from the gorilla and chimpanzee facial skeletons were used. Cortical specimens were scanned with a Scanco MicroCT 35 at a resolution of 3.5 microns. Apparent and material densities were estimated using Scanco’s calibrations. Results showed variation in cortical density varying between 1400 and 2000 mg/ccm. MicroCT estimates of apparent density were lower ranging from 700 to 1000 mg/ccm yet were highly correlated with values measured by standard technique at R=0.95. Material density was correlated at a significant but lower level (R=0.75). These findings suggest that microCT can be used to assess continuous variations in apparent bone density and might be useful for gathering material property data for use in finite element studies of primate craniofacial skeletal function.
This study was funded by the National Science Foundation Physical Anthropology HOMINID program (NSF BCS 0725141).