**Core Concept**
Paget's disease, also known as Osteitis Deformans, is a chronic bone disorder characterized by abnormal bone remodeling and excessive bone resorption, leading to deformities and skeletal complications. Treatment aims to control the disease process, alleviate symptoms, and prevent fractures.

**Why the Correct Answer is Right**
The primary treatment for Paget's disease involves medications that inhibit bone resorption, reduce disease activity, and prevent skeletal complications. Bisphosphonates, such as alendronate and risedronate, are commonly used to control bone turnover and reduce pain. Calcitonin and bisphosphonate combinations are also effective in managing the disease.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the treatment of Paget's disease does not typically involve corticosteroids, which are more commonly used to treat inflammatory conditions.
**Option B:** This option is incorrect because estrogens are not a primary treatment for Paget's disease, although they may be used to manage related conditions such as osteoporosis.
**Option C:** This option is incorrect because calcitriol, or vitamin D3, is not a primary treatment for Paget's disease, although it may be used to manage related conditions such as osteomalacia.

**Clinical Pearl / High-Yield Fact**
Bisphosphonates are the first-line treatment for Paget's disease due to their efficacy in reducing bone turnover and preventing skeletal complications. However, long-term use of bisphosphonates can lead to atypical femoral fractures and osteonecrosis of the jaw.

**Correct Answer: D.**