A disease of bone that initially results in the excessive resorption of bone (by osteoclasts) followed by the replacement of normal bone marrow with vascular and fibrous tissue. The disease is Monarch Disease Ontology term MONDO_0005382 (bone Paget disease). Also known as: Paget disease of bone, Paget's bone disease, Paget's disease of bone, Paget's disease of the bone, Pagets disease (bone), bone Paget's disease, osseous Paget's disease, osteitis deformans.