DMFT Index — MFDS Part 1 MCQ
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Correct answer: D — The number of permanent teeth that are decayed, missing because of caries, or filled
The correct answer is D. DMFT is the standard epidemiological index of lifetime caries experience in the permanent dentition: D counts decayed teeth, M counts teeth missing because of caries, F counts filled teeth, and T signifies that whole teeth are the counting unit. The three components are summed to give a cumulative score (maximum 28 or 32 depending on whether third molars are included). Option E describes the lowercase dmft index, which UK surveys (for example the national survey of 5-year-olds) use for the primary dentition. Option C describes DMFS, the surface-level variant, which is more sensitive but is a different index. Option A captures only the untreated D component, ignoring restored teeth and caries-related tooth loss. DMFT is an absolute count, not a percentage, so E is wrong.
Reference: Derby and Derbyshire Oral Health Needs Assessment (UK local authority/NHS public health report), section on measuring tooth decay (dmft/DMFT definitions), September 2024. https://observatory.derbyshire.gov.uk/wp-content/uploads/reports/documents/health/specialist_reports_and_assessments/2024/DD%20Oral%20Health%20Needs%20Assessment%20Sep24%20final%20version.pdf