A panoramic radiograph shows a well-defined homogeneous radiopacity where the mandibular second premolar should be, with no root resorption, no radiolucent rim, and no association with any tooth. What is the diagnosis?

Correct answer: A. Idiopathic osteosclerosis

• A. Correct. A dense, well-defined radiopacity with no radiolucent rim, no expansion, no resorption and no relationship to a tooth or inflammatory source is idiopathic osteosclerosis (dense bone island) — a normal variant requiring no treatment.
• B. An osteoma produces bony expansion and is often peripheral; multiple osteomas suggest Gardner syndrome.
• C. Condensing osteitis is by definition associated with a tooth having pulpal inflammation.
• D. Cementoblastoma is fused to a root and surrounded by a radiolucent rim.