Bone mineralization: from tissue to crystal in normal and pathological contexts.

Bone is a complex and structured material; its mechanical behavior results from an interaction between the properties of each level of its structural hierarchy. The degree of mineralization of bone (bone density measured at tissue level) and the characteristics of the mineral deposited (apatite crystals) are major determinants of bone strength. Bone remodeling activity acts as a regulator of the degree of mineralization and of the distribution of mineral at the tissue level, directly impacting bone mechanical properties. Recent findings have highlighted the need to understand the underlying process occurring at the nanostructure level that may be independent of bone remodeling itself. A more global comprehension of bone qualities will need further works designed to characterize what are the consequences on whole bone strength of changes at nano- or microstructure levels relative to each other.