Edentulation alters material properties of cortical bone in the human mandible

Ridge resorption following edentulation has been documented clinically, but the effects of tooth loss on the material properties of mandibular cortical bone have received little study. Material properties and their structural basis are essential for our understanding of bone quality in the edentulous mandible and are of interest as a tissue-level model for functional adaptation. This study's aim was to determine material property variability in the edentulous mandible, and to compare it with data from a previous study of dentate mandibles. Forty-four cortical samples were removed from each of 10 adult fresh edentulous mandibles. Cortical thickness and density were measured. Material properties were calculated from ultrasonic velocities. Mandibular cortical bone in the edentulous mandibles differed from that of dentate mandibles in cortical thickness, elastic and shear moduli, anisotropy, and orientation of the axis of maximum stiffness. These results suggest that cortical microstructural changes accompany ridge resorption following edentulation.