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Nolla Classification — NDEB AFK MCQ

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HardPaediatric DentistryNolla ClassificationNDEB AFK

According to the Nolla classification, at which stage of root development is a tooth considered to have a closed apex?

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: D — Stage 10

The Nolla classification describes 10 stages of tooth development. Stage 10 is the final stage where the root apex is completely closed. Stage 9 represents root completion with the apex almost closed. Stage 8 shows two-thirds of root completed. Stage 6 shows crown completion. Understanding Nolla stages is important for timing orthodontic treatment, assessing eruption, and predicting root development in paediatric patients.

Reference: Nolla – Development of the Human Dentition, ASDC J Dent Child, 1960