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Browridge morphology & hominid evolution: is there any evidence for a mechanical influence?
Author(s) -
Dechow Paul C.,
Wang Qian,
Peterson Jill
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.174.1
Subject(s) - crania , cortical bone , anatomy , morphology (biology) , resorption , maxilla , cranial vault , bone resorption , strain (injury) , dentistry , materials science , skull , biology , medicine , pathology , genetics
If low bone strain during orofacial function in living individuals indicates that adaptations in browridge morphology during human evolution have little to do with such function, than we might expect that the loss of function has little effect on browridge structure. This study determined cortical material properties in edentulous crania and evaluated differences with dentate crania. Cortical bone from 15 edentulous skulls were measured for thickness, density, and elastic properties. Data were compared to that of dentate crania. Cortical bone from all regions of edentate facial skeletons, including the supraorbit, is thinner than in dentate skulls. Elastic and shear moduli, and density are similar or greater in the zygoma, browridges, and cranial vault, while these properties are less in the maxilla. Most cortical bone, especially in edentulous maxillae, has reduced anisotropy, and is less oriented. The loss of significant occlusal loads following edentulation may contribute to changes in material properties and orientation during bone remodeling. These results suggest that area specific cortical microstructural changes accompany bone resorption following edentulation. This effect is also found in low load areas like the browridges, suggesting that strain magnitudes alone are insufficient to suggest that function has no impact on morphology in low strain regions. Funding: NSF BCS 0725126.