Pamidronate, an aminobisphosphonate, is a potent inhibitor of bone resorption. The purpose of this protocol is to evaluate the effectiveness of pamidronate in children with types III and IV osteogenesis imperfecta when the cycle time is varied. We plan to compare children treated with pamidronate on an every-three-month infusion cycle to children treated every six months with the same dose per infusion. We also plan to continue to compare children treated with pamidronate and growth hormone to children treated with pamidronate alone.