Therapeutic approaches to bone diseases

The strength and integrity of our bones depends on maintaining a delicate b alance between bone resorption by osteoclasts and bone formation by osteobl asts. As we age or as a result of disease, this delicate balancing act beco mes tipped in favor of osteoclasts so that bone resorption exceeds bone for mation, rendering bones brittle and prone to fracture, A better understandi ng of the biology of osteoclasts and osteoblasts is providing opportunities for developing therapeutics to treat diseases of bone. Drugs that inhibit the formation or activity of osteoclasts are valuable for treating osteopor osis, Paget's disease, and inflammation of bone associated with rheumatoid arthritis or periodontal disease. Far Less attention has been paid to promo ting bone formation with, for example, growth factors or hormones, an appro ach that would be a valuable adjunct therapy for patients receiving inhibit ors of bone resorption.