Idiopathic Osteosclerosis — ORE Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

ModerateRadiology & ImagingIdiopathic OsteosclerosisORE Part 1

A 50-year-old patient has an incidental finding on a periapical radiograph of a lower premolar. There is a 5 mm, well-defined, uniformly radiopaque focus adjacent to the root apex. The associated tooth is vital. The root outline is intact and separate from the opacity, and there is no radiolucent rim. What is the most likely diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Idiopathic osteosclerosis

The diagnosis is **A, idiopathic osteosclerosis**. This is an incidental, non-expansile dense bone focus, typically seen in the posterior mandible, which may be superimposed on or lie close to a tooth apex. The decisive features are the homogeneous radiopacity, intact and separate root outline, vital tooth and absence of a radiolucent rim. **Cementoblastoma** is fused to the root and is usually surrounded by a thin radiolucent halo. **Hypercementosis** enlarges the root contour rather than producing a separate bone opacity. Mature **periapical cemento-osseous dysplasia** can be radiopaque around vital teeth, but usually has a surrounding radiolucent zone and classically affects mandibular anterior teeth. An **osteoma** is usually a larger, expansile lesion rather than a small periapical dense bone island.

Reference: Borges F, et al. An updated review of idiopathic osteosclerosis of the jaws. 2021. https://pubmed.ncbi.nlm.nih.gov/35491138/