Control of bone formation and resorption: biological and clinical perspective.

Bone is subject to continuous breakdown (resorption) by osteoclasts and rebuilding (formation) by osteoblasts in order to fulfill its functions. Most bone diseases including osteoporosis are due to excessive bone resorption relative to formation. Recent research has generated new insights into the regulation of osteoclast and osteoblast differentiation and function and the interaction between the two cell types. There is increased awareness of the role of mechanical stimuli in bone homeostasis and by inference the function of bone cells. This information can lead to new therapeutic modalities for maintaining a healthy skeleton into old age.