Pathology · patient case with 1 question
Brown-yellowish teeth on bitewing
Scenario: A male patient accompanying his mother is worried because his teeth look BROWN/YELLOWISH. A bitewing radiograph is provided.
Question 1
What is the diagnosis?
Show answer and explanation
Correct answer: A. Amelogenesis imperfecta
- A. Correct. Amelogenesis imperfecta is a defect of ENAMEL formation affecting BOTH dentitions and ALL teeth. In the hypoplastic/hypomineralised forms, thin or absent enamel exposes the underlying dentin and gives the yellow-brown appearance. Radiographically the enamel layer is thin, absent, or shows a density approaching that of dentin — which is what makes it 'easy to distinguish on the radiograph', as the recaller noted.
- B. Tetracycline staining is INTRINSIC discoloration in bands corresponding to the timing of drug exposure, and is not associated with abnormal enamel thickness on radiographs.
- C. Dentinogenesis imperfecta gives opalescent blue-grey to amber teeth with BULBOUS crowns, cervical constriction, short roots and OBLITERATED pulp chambers — a very different radiographic picture.
- D. Fluorosis is symmetrical and generalised, ranging from white flecking to brown staining with pitting, and correlates with excess fluoride during tooth formation; the enamel THICKNESS is normal radiographically.
Note: Radiographic shortcut: AI = the ENAMEL is abnormal (thin/absent, poor contrast with dentin). DI = the DENTIN is abnormal (bulbous crowns, obliterated pulps, short roots).