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Dentistry · Orthodontics and paediatric dentistry: dental trauma sequelae
Sample itemSix years after an upper incisor was replanted late following avulsion, the tooth is immobile and produces a high, metallic sound on percussion. Radiographs show loss of the periodontal ligament space. What is the diagnosis?
Original practice item, not a recalled exam question. Nothing here is recorded.
The answer and the reasoning
A. Replacement resorption (ankylosis)
When the periodontal ligament is lost after prolonged drying, bone fuses to the root and gradually replaces it. The tooth is ankylosed, gives a metallic percussion note and becomes infraoccluded in the growing child.
Option by option
A. Replacement resorption (ankylosis) (correct)
Correct. Absent PDL space and a metallic note indicate ankylosis with replacement resorption.
B. Hypercementosis
Hypercementosis thickens the root and preserves the ligament space.
C. Internal resorption
Internal resorption enlarges the pulp canal from within.
D. Acute apical abscess
An abscess is tender and has a widened ligament space.
Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.
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