Pathology · single question
A vital tooth has a radiopaque mass fused to its root apex with a radiolucent halo and cortical bone expansion. What is the diagnosis?
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Correct answer: B. Cementoblastoma
Cementoblastoma: classic features are (1) vital tooth, (2) radiopaque mass fused to root apex — cannot be separated, (3) radiolucent halo surrounding the mass, (4) cortical expansion, (5) most common in mandibular first molar region. Treatment: extraction of the tooth WITH the attached lesion. Root resorption may be present.
- A. ❌ PCOD shows mixed lesions in the periapical region of lower anterior teeth — does NOT fuse to the root and lacks the radiolucent halo with cortical expansion.
- B. ✅ Cementoblastoma — vital tooth + radiopaque mass fused to root + radiolucent halo + cortical expansion = pathognomonic.
- C. ❌ Hypercementosis is excess cementum deposition; no cortical expansion and no radiolucent halo.
- D. ❌ Focal sclerosing osteomyelitis is a radiopaque lesion at the apex of a tooth with caries/pulpitis — no halo or cortical expansion.