Normal and abnormal bone remodeling in man.

Remodeling is a continuous process of skeletal destruction and renewal, occurring throughout life in humans and some other mammals. Remodeling minimizes the damage of routine wear but, because of its fundamental inefficiency, also underlies normal age-related bone loss. Alterations in bone mass due to dietary and endocrine factors occur in response to changes in the birthrate of new remodeling units, increased remodeling imbalance within existing units, or a combination of both. Familiarity with remodeling is prerequisite to understanding the pathologic basis and rational therapy of metabolic bone disease.