Patient description: The patient is a 53-year-old man complaining of frequent headaches, generalized bone pain and difficulty chewing that started 6 years ago and is getting worse. Examination shows bilateral swellings around the molars. The swellings have increased since his last examination. Several extraoral lesions of the head and face are detected. The swellings are non-tender and attached to the underlying bone. Further evaluation shows increased uptake of radioactive substance as well as an increase in urinary pyridinoline. The serum alkaline phosphatase is 300 IU/L (the normal range is 44- 147 IU/L). The patient's sister had the same problems. She was diagnosed with Paget's disease of bone when she was 52 years old. The diagnosis of Paget's Disease of Bone is confirmed and Bisphosphonate will be started as first-line therapy.

Clinical trial eligibility criteria: eligible ages (years): 40.0-85.0,  Osteoporosis Osteoporosis, Age-Related Osteoporosis Localized to Spine Age Related Osteoporosis Osteoporosis Senile Osteoporosis of Vertebrae Healthy ambulatory male from 40 to 85 years of age (inclusive) with primary osteoporosis or osteoporosis associated with hypogonadism The patient has a BMD T-score (based on the female reference range as assessed by the central imaging vendor) of ≤ -2.5 at the lumbar spine (L1-L4) or hip (femoral neck or total hip) by DXA or ≤-1.5 and with radiologic evidence of vertebral fracture or a documented history of low-trauma nonvertebral fracture sustained in the past 5 years. Men older than 65 years may be enrolled if they have a BMD T-score ≤ -2.0 even if they do not meet the fracture criteria Normal medical history, physical examination, including vital signs, and body mass index (BMI) Hypogonadal patients whose doses of androgens have been stable for at least twelve months before randomization are eligible and may continue therapy during the study Laboratory tests within the normal range including serum calcium (albumin-corrected), PTH, serum phosphorus and alkaline phosphatase, and thyroid stimulating hormone (TSH) values  Presence of abnormalities of the lumbar spine that would prohibit assessment of spinal bone mineral density, defined as having at least 2 radiologically evaluable vertebrae within L1-L4 A BMD T-score of ≤-3.5 at the total hip, femoral neck, or lumbar spine based upon the female reference range Unevaluable hip BMD or patients who have undergone bilateral hip replacement Fragility fracture within the prior twelve months History of severe vertebral fracture or >2 moderate vertebral fractures History of bone disorders (e.g., Paget's disease) other than osteoporosis Patients with clinical signs of hypogonadism present at screening who plan to initiate testosterone replacement History of prior external beam or implant radiation therapy involving the skeleton other than radioiodine History of chronic or recurrent renal, hepatic, pulmonary, allergic, cardiovascular, gastrointestinal, endocrine, central nervous system, hematologic or metabolic diseases, or immunologic, emotional and/or psychiatric disturbances to a degree that would interfere with the interpretation of study data or compromise the safety of the patient History of Cushing's disease, growth hormone deficiency or excess, hyperthyroidism, hypo