Age, period, and cohort analysis of regular dental care behavior and edentulism: A marginal approach

<p>Abstract</p> <p>Background</p> <p>To analyze the regular dental care behavior and prevalence of edentulism in adult Danes, reported in sequential cross-sectional oral health surveys by the application of a marginal approach to consider the possible clustering effect of birth cohorts.</p> <p>Methods</p> <p>Data from four sequential cross-sectional surveys of non-institutionalized Danes conducted from 1975-2005 comprising 4330 respondents aged 15+ years in 9 birth cohorts were analyzed. The key study variables were seeking dental care on an annual basis (ADC) and edentulism. For the analysis of ADC, survey year, age, gender, socio-economic status (SES) group, denture-wearing, and school dental care (SDC) during childhood were considered. For the analysis of edentulism, only respondents aged 35+ years were included. Survey year, age, gender, SES group, ADC, and SDC during childhood were considered as the independent factors. To take into account the clustering effect of birth cohorts, marginal logistic regressions with an independent correlation structure in generalized estimating equations (GEE) were carried out, with PROC GENMOD in SAS software.</p> <p>Results</p> <p>The overall proportion of people seeking ADC increased from 58.8% in 1975 to 86.7% in 2005, while for respondents aged 35 years or older, the overall prevalence of edentulism (35+ years) decreased from 36.4% in 1975 to 5.0% in 2005. Females, respondents in the higher SES group, in more recent survey years, with no denture, and receiving SDC in all grades during childhood were associated with higher probability of seeking ADC regularly (<it>P </it>< 0.05). The interaction of SDC and age (<it>P </it>< 0.0001) was significant. The probabilities of seeking ADC were even higher among subjects with SDC in all grades and aged 45 years or older. Females, older age group, respondents in earlier survey years, not seeking ADC, lower SES group, and not receiving SDC in all grades were associated with higher probability of being edentulous (<it>P </it>< 0.05).</p> <p>Conclusions</p> <p>With the use of GEE, the potential clustering effect of birth cohorts in sequential cross-sectional oral health survey data could be appropriately considered. The success of Danish dental health policy was demonstrated by a continued increase of regular dental visiting habits and tooth retention in adults because school dental care was provided to Danes in their childhood.</p

Restorative caries treatment patterns in Danish 20-year-old males in 1986 and 1991

This study examines the restorative caries treatment pattern in Danish 20-year-old military conscripts in 1986 and 1991. The study groups comprised 85 and 164 males born in 1966 and 1971, respectively. The examination was performed as a part of the routine for each conscript according to directions from Dental Service, Danish Defense Forces and included surface recording of fillings on all teeth except third molars. Two bitewing radiographs were taken of all conscripts in the 1986-group and of those who gave permission (59) in the 1991-group. The mean number of filled surfaces was 10.2 and 8.8 in 1986 and in 1991, respectively. 80% of the occlusal surfaces on permanent first molars were filled in the 1986-group and filled or sealed in the 1991-group in contrast to 45% of permanent second molars. Data from maxillary molars indicated a tendency to placement of fillings related to tooth specific morphology whereas extended fillings involving the entire occlusal surface dominated on mandibular molars. The X-ray examination disclosed that the majority of approximal molar surfaces were classified as sound in both study groups. Less than 1% of the approximal molar surfaces were recorded as having lesions penetrating deep into the dentin. In 1981 and in 1986 the participants in the study groups were 15 yr old. In these years the mean number of filled surfaces in Danish children amounted to 11.0 and 6.9 respectively, which indicates that very few lesions in need of operative treatment developed from age 15 to age 20 in both study groups