Influence of School Type and Class Level on Mean Caries Experience in 12-Year-Olds in Serial Cross-Sectional National Oral Health Survey in Germany-Proposal to Adjust for Selection Bias.

The objective of this study is to analyse the effects of attended school type and class level on the reported caries experience (DMFT) obtained in the serial cross-sectional National Oral Health Study in Children in Germany (NOHSC) for the WHO reference group of 12-year-olds. METHODS: Caries data from the 2016 NOHSC were adjusted for each federal state on the basis of two additional large-scale datasets for school type and class level. RESULTS: Twelve-year-olds in all grades in Saxony-Anhalt (n = 96,842) exhibited significantly higher DMFT values than 12-year-olds in 6th grade (n = 76,456; +0.10 DMFT; ~14.2%, p < 0.001). Adjustments for school type had effects on DMFT on the level of federal states but almost balanced out on the national level (-0.01 DMFT; ~2%). Due to putatively similar structures of the federal states, the national mean DMFT for 12-year-olds in the latest NOHSC (2016; n = 55,002) was adjusted from 0.44 to 0.50 DMFT, correcting for selection bias. CONCLUSION: Selection bias in this NOHSC leads to an underestimation of caries levels by about 15%. Due to very low caries experience in children in Germany, these precise adjustments (+0.06 DMFT) have only a minor effect on interpretations of the national epidemiologic situation. Consequently, other national caries studies worldwide using the robust marker of DMFT should also adjust for systematic selection bias related to socio-economic background rather than increasing efforts in examination strategy.

[Oral health trends in children : Results from the epidemiological surveys accompanying group prophylaxis in Germany]. / Mundgesundheitstrends im Kindesalter : Ergebnisse aus den epidemiologischen Begleituntersuchungen zur Gruppenprophylaxe in Deutschland.

To describe the current epidemiological trends in the dental caries experiences of children in Germany, oral health data was primarily presented on the basis of the Epidemiological Studies Accompanying Group Prophylaxis (DAJ study) for the 2015/16 schoolyear. Caries data of 301,684 children from three different age groups were available. The trends in caries development were based on previous national and regional studies conducted in Germany.Caries in the primary dentition occur very early (approx. 10-17% of 3­year-olds) and are still widespread among 6­ to 7­year-olds (approx. 40-60%). The proportion of unrestored decayed primary teeth is very high (3-year-olds: 73.9%; 6 to 7­year-olds: 42.5%). There has also been no significant improvement among 6­ to 7­year-olds in the last 10 years. The values for the 3­year-olds that were nationally examined for the first time in the DAJ study are in the range of previous regional studies from recent decades. Caries prevalence among the 6­ to 7­year-olds shows a regional convergence. Among the 12-year-olds, mean caries experience in the permanent dentition has fallen by about 80% in the last 20 years. Regarding oral health in this age group, Germany ranks highest among countries worldwide.There is still a substantial need for oral health improvement in the primary dentition of children in Germany. Recently implemented preventive measures already focus on tackling this problem. Further improvements in caries prevention similar to those in the permanent dentition are feasible and expected.