Enamel Maturation — NDEB AFK MCQ

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HardBiomedical SciencesEnamel MaturationNDEB AFK

Enamel maturation involves the removal of which organic component by ameloblasts during the transition from secretory to maturation stage?

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Correct answer: C — Amelogenin

During enamel maturation, ameloblasts transition from secretory to maturation stage and actively remove the organic matrix proteins (primarily amelogenin, which comprises ~90% of the matrix) through endocytosis and enzymatic degradation (by MMP-20 and KLK-4). Water is also removed. This allows further mineral deposition, increasing the inorganic content from ~30% (secretory stage) to ~96% (mature enamel). Defective removal of amelogenin (KLK-4 mutations) causes hypomaturation-type amelogenesis imperfecta with soft, opaque enamel.

Reference: Nanci – Ten Cate's Oral Histology, 9th ed., 2017