Radiology · single question
A 17-year-old patient's panoramic radiograph shows both maxillary second premolars (#15 and #16 area) unerupted. The most likely cause is:
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Correct answer: A. Ankylosis of the teeth
- A. Correct. Bilateral uneruption of teeth in a teenager, especially when the radiograph shows no obvious cyst or lack of space, is most consistent with ankylosis. Ankylosis (fusion of cementum/dentin to alveolar bone) prevents eruption of the affected teeth.
- B. Inadequate arch length can cause impaction but typically affects third molars — in a 17-year-old with bilateral premolar impaction, ankylosis is more likely.
- C. Dentigerous cyst could cause impaction but would need radiographic evidence of a cyst.
- D. Sinus attachment is not a recognized cause of tooth impaction.