Microstructural basis of elastic properties of cortical bone in baboon mandibles

Abstract

Successful bone regeneration in reconstructive surgery should go beyond reproducing shape and structure to restore biological and mechanical function as well as long‐term integration with surrounding native tissues. Recent work has demonstrated that the three‐dimensional material properties of cortical bone vary throughout craniofacial skeletons. However, how the bone microstructure is related to the mechanical properties of bone at the tissue level throughout the skull needs systematic investigation. Cortical samples from symphyseal, corporal and ramal areas of a baboon mandible were studied using micro‐CT and ultrasonic techniques. Results demonstrated that there were significant variations in elastic properties, porosity, and morphology of osteonal canals throughout the baboon mandible, and the principal orientation of osteonal canals agreed well with the axis of maximum stiffness, and further with the long axis of the bone in three functional areas. These findings on the relationships between bone material properties and microstructure, and their relationships to the skeletal form and function at the organ level will greatly enhance our ability to address questions derived from both evolutional and craniofacial medicine fields about the development and biomechanics of skulls. Supported by NSF HOMINID grants (BCS 0725141, 0725183), MEDCEN, and Mercer Seed.