MJDF Dental Public Health & Evidence-Based Dentistry

Question 1

What is the DMFT index used to measure at the population level?

Accepted Answer

Caries experience in the permanent dentition — Decayed, Missing (due to caries), Filled Teeth — used to compare populations and monitor trends

Answer

DMFT (and its primary tooth equivalent dmft) quantifies lifetime caries experience, allowing comparison between countries, regions, and time periods; the WHO target has been 'DMFT ≤1 at age 12' as a key global benchmark.

Question 2

What is the current WHO target for DMFT at age 12?

Accepted Answer

DMFT ≤1 at age 12 (longstanding target, with newer frameworks using multiple indicators)

Answer

The WHO global oral health target of DMFT ≤1 at age 12 has been a benchmark since 1981; newer WHO frameworks use multiple indicators beyond DMFT, but this remains a key internationally recognised standard.

Question 3

What is the main limitation of the DMFT index in assessing oral health need?

Accepted Answer

It does not distinguish between active and treated disease, overestimates need if many filled teeth, and underestimates need if many extractions occur instead of restoration

Answer

DMFT counts fillings as equal to decay (both contribute equally to the score), missing teeth may mask different care patterns (extraction vs. restoration), and it does not capture disease severity or impact on quality of life.

Question 4

What is the oral health impact profile (OHIP-14) used to measure?

Accepted Answer

Oral health-related quality of life (OHRQoL) — how oral conditions affect physical, psychological, and social wellbeing

Answer

OHIP-14 is a 14-item validated questionnaire measuring the functional, psychological, and social impacts of oral conditions on quality of life — an essential patient-centred outcome measure.

Question 5

What is the purpose of water fluoridation in public health dentistry?

Accepted Answer

Population-level caries prevention — optimal fluoride (0.7–1.0 mg/L in UK) reduces DMFT by approximately 25–30% without significant health risk

Answer

Community water fluoridation adjusts fluoride concentration to 0.7–1.0 ppm (mg/L), providing a constant low-level fluoride exposure that reduces caries incidence across all socioeconomic groups.

MJDF Part 1 Practice Test

MJDF Part 1 Practice Test

MJDF Dental Public Health & Evidence-Based Dentistry