Elastic modulus variation in mandibular bone: A microindentation study of Macaca fascicularis
Version of Record online: 30 NOV 2007
Copyright © 2007 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 135, Issue 1, pages 100–109, January 2008
How to Cite
Rapoff, A. J., Rinaldi, R. G., Hotzman, J. L. and Daegling, D. J. (2008), Elastic modulus variation in mandibular bone: A microindentation study of Macaca fascicularis. Am. J. Phys. Anthropol., 135: 100–109. doi: 10.1002/ajpa.20714
- Issue online: 14 DEC 2007
- Version of Record online: 30 NOV 2007
- Manuscript Accepted: 8 AUG 2007
- Manuscript Received: 27 APR 2007
We characterized the heterogeneous anisotropic elastic properties of mandibular bone in an adult female specimen of Macaca fascicularis using the technique of microindentation. This approach used an indenter of known mass and geometry to sample bone hardness at a spatial resolution in the order of 100 μm. Hardness values were converted to elastic modulus using empirically derived regression. We determined properties in alveolar, midcorpus, and basal regions of coronal and transverse sections taken from multiple locations along the corpus and ramus. Within sections, we determined properties from endosteal, midcortical, and periosteal regions. We found regional variations in bone structure, including bands of orthotropic circumferential lamellar bone at the endosteal and periosteal corpus base, angular region, and ramus. Transversely isotropic osteonal bone characterizes the midcortices of alveolar and basal regions, with many resorption spaces in alveolar regions restricting sampling opportunities. Regional variations in elasticity include relatively compliant bone in the anterior corpus and ramus. Basal cortical bone is stiffer longitudinally than transversely or superoinferiorly, while the evidence for directional dependence in alveolar bone is equivocal. Alveolar bone appears to be relatively compliant with respect to bone found in midcorpus or basal regions. Considerable variation exists in structure and material properties on a highly localized scale, more so than is discernible through conventional approaches for determining material property variation. Am J Phys Anthropol, 2008. © 2007 Wiley-Liss, Inc.