[Bone and joint diseases in children. Abnormal bone mineral density in children].

In recent years, the problem of osteoporosis is increasingly raised in children as well as adults both as a primary disorder and as secondary results to various diseases, medications, and lifestyle issues. On the other hand, molecular mechanisms of pathogenesis have been elucidated in several sclerosing disorders contributing to our understanding of basic biology of bone metabolism. In this chapter, we reviewed the recent progress on the method to evaluate BMD in growing period and etiologies of abnormal BMD in children.