Amelogenesis Imperfecta Hypoplastic — ORE Part 1 MCQ

Correct answer: D — Amelogenesis imperfecta (hypoplastic type)

Amelogenesis imperfecta (hypoplastic type) is the correct diagnosis. The hypoplastic variant results from a secretory defect during enamel formation, producing thin, well-mineralized enamel with characteristic surface pits and grooves. The clinical presentation—yellow-brown teeth, reduced enamel thickness, rough pitted surfaces across the entire dentition—combined with radiographic findings of thin enamel with reduced radiodensity and altered enamel-dentine contrast, are pathognomonic for hypoplastic AI. The strong familial pattern (mother and siblings affected) confirms inherited aetiology consistent with autosomal dominant inheritance, common in hypoplastic AI. Dental fluorosis affects enamel thickness minimally and lacks familial patterning of this severity. Dentinogenesis imperfecta primarily affects dentine, not enamel thickness. Molar-incisor hypomineralisation affects only specific teeth, not the entire uniform dentition. Tetracycline staining causes discolouration without structural enamel reduction or familial inheritance.

Reference: Diversity of clinical, radiographic and genealogical findings in 41 families with amelogenesis imperfecta. Dong J, Ruan W, Duan X. Oral Disease 2023; 29(6):2334–2365. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6442841/