Which clinical finding BEST supports a diagnosis of amelogenesis imperfecta rather than localised enamel damage?

Correct answer: D. Generalised grooving and pitting distributed over the smooth surfaces of ALL teeth in BOTH dentitions

• A. Cervical facial enamel loss on selected teeth is a wear pattern — abrasion, abfraction or erosion — not a developmental defect.
• B. Sharply demarcated opacities of a limited chronological band suggest fluorosis or molar-incisor hypomineralisation, both of which are ACQUIRED and affect only teeth mineralising during the insult.
• C. A single localised discolouration on one tooth points to a local cause — trauma or infection of the primary predecessor (Turner tooth), or simply extrinsic staining.
• D. CORRECT. Amelogenesis imperfecta is a GENETIC defect of the enamel-forming apparatus, so it is by definition GENERALISED and affects BOTH the primary and the permanent dentitions. The hypoplastic type gives thin enamel with generalised pitting and grooving over the smooth surfaces; the hypomineralised/hypomaturation types give soft, opaque, discoloured enamel that chips readily. Symmetry and universality across both dentitions are the diagnostic signature.

Note: Sort defects by DISTRIBUTION: generalised + both dentitions = genetic (AI, DI); a chronological band across teeth of the same developmental age = systemic insult (fluorosis, febrile illness, tetracycline); a single tooth = local insult (Turner tooth, trauma).