• DMF index;
  • epidemiology;
  • quasi-longitudinal differences;
  • oral health;
  • time-lag differences

Abstract –

The purpose of this paper is to describe the changes in the oral health of adults from Trendelag, Norway, over two decades (1973–1983–1994), from both a quasi-longitudinal and a time-lag perspective. Study participants were selected by random sampling in 1973, 1983 and 1994 (n=1759, n=3195, n=2341). Data were collected by epidemiological registrations and questionnaires. Oral health was measured by the additive DMF index. The number of decayed teeth was low in all age groups in 1994. There was a reduction in the number of filled teeth from 1983 to 1994 in the time-lag perspective in the youngest age group and the urban middle-aged group. The rural middle-aged adults and the older adults showed more filled teeth in 1994 than in 1983. In a quasi-longitudinal perspective, no significant changes in the 1960 birth cohort and the 1939–48 urban birth cohort were shown from 1983 to 1994, while the 1930–38 birth cohort and 1939–48 rural birth cohort acquired more filled surfaces during this period. There are now at least two different oral health populations of adults. The younger with the potential to carry oral health benefits into old age, and an elderly population burdened with extensive treatment but keeping their natural teeth.