Dental Public Health
What the exam tests
Dental Public Health tests epidemiology, prevention at population level, service planning, and critical appraisal. Questions ask you to measure disease, choose an intervention, and evaluate it without confusing individual care with public health.
Core rules
- Prevalence is the proportion with disease at a point in time; incidence is new cases over time. dmft counts decayed, missing, filled primary teeth; DMFT does the same for permanent teeth.
- Caries measurement should specify thresholds; ICDAS records early lesions, while dmft/DMFT usually counts cavitated lesions.
- Prevention uses the common risk factor approach: sugar control, fluoride, tobacco and alcohol control, and oral hygiene.
- Water fluoridation is a population measure; fluoride varnish and sealants are targeted measures. Choose according to need, evidence, and equity.
- Screening must have a suitable test, acceptable uptake, and a clear referral pathway. Sensitivity and specificity describe test performance; positive predictive value depends on prevalence.
- Evaluate programmes with baseline and follow-up data, not anecdotes.
Worked example
A municipality has high caries prevalence in 5-year-olds and wide inequalities. A plan starts with a baseline survey using standard criteria, then combines water fluoridation or fluoride varnish for high-risk schools, supervised toothbrushing, sugar-sweetened beverage policies, and workforce planning. Evaluation uses repeat surveys, caries increment, and process measures such as uptake. The reasoning is that population measures reduce exposure for everyone, while targeted measures reach high-risk groups.
Traps
- Confusing prevalence with incidence.
- Comparing dmft and DMFT directly.
- Planning prevention without baseline data.
- Assuming a screening test with high sensitivity is automatically useful.