Trajectory of social inequalities in the treatment of dental caries among preschool children in Japan.

The longitudinal trend of dental health inequalities among preschool children has not been described. In this study, we aimed to measure the trajectory of both relative and absolute inequalities in caries treatment among preschool children in Japan. We used data from the Longitudinal Survey of Babies in the 21st Century (LSB21), which is an ongoing national representative longitudinal study. The target population was families residing in Japan with newborn baby/babies born between 10 January and 17 January or 10 July and 17 July 2001. Data regarding caries treatment history and socioeconomic status (SES) were collected using a self-reported questionnaire. SES was assessed on the basis of the parents' educational attainment. In total, 35 260 children were followed from 2.5 to 5.5 years through annual surveys. To evaluate absolute and relative inequalities, we calculated the slope index of inequality (SII) and relative index of inequality (RII), respectively. The rate of caries treatment at the age of 2.5 years was <10% for all SES groups; this increased to more than 30% at 5.5 years of age. Children with lower SES received more frequent caries treatment, and both absolute and relative social inequalities were statistically significant. SII showed a significant increase throughout the follow-up period, with values of 4.13% (95% confidence interval [CI], 3.16; 5.09) and 15.50% (95% CI, 13.68; 17.32) at 2.5 and 5.5 years of age, respectively. In contrast, RII decreased with an increase in the treatment rate for all groups, with values of 1.83 (95% CI, 1.59; 2.11) and 1.53 (95% CI, 1.46; 1.61) at 2.5 and 5.5 years of age, respectively. Our results suggest that the rate of caries treatment is higher for preschool children with lower SES in Japan, with significant widening of absolute inequalities along with the growth of the children.

Aida J ，Matsuyama Y ，Tabuchi T ，Komazaki Y ，Tsuboya T ，Kato T ，Osaka K ，Fujiwara T ... -  《-》

Association between socioeconomic status and dental caries among Chinese preschool children: a cross-sectional national study.

Socioeconomic inequalities in oral health are often neglected in oral health promotion. This cross-sectional study assessed the association between dental caries and socioeconomic status (SES) among preschool children in China. Cross-sectional study. Data from the Fourth National Oral Health Survey of China (2015), comprising of 40 360 children aged 3-5 years was used. Dental caries indicators including prevalence of dental caries, dental pain experience and number of decayed, missing and filling teeth (dmft). SES indicators included parental education and household income. The associations between SES and dental caries were analysed by using negative binomial regression or Poisson regression models according to data distribution. Relative and absolute inequalities in dental caries were quantified by using the Relative Index of Inequality (RII) and Slope Index of Inequality (SII), respectively. There were significant associations between SES and prevalence of dental caries and dmft (p<0.001). Children from lower educated (RII 1.36, 95% CI 1.3 to 1.43; SII 0.97, 95% CI 0.81 to 1.13) and lower household income (RII 1.17, 95% CI 1.11 to 1.24; SII 0.55, 95% CI 0.35 to 0.75) families had higher dmft than those from well-educated and most affluent families. Relative and absolute inequalities in dental caries were larger in urban areas by household income, and in rural areas by parental education. Association between dental caries and SES was demonstrated and socioeconomic inequalities in dental caries existed among Chinese preschool children.

Zhang T ，Hong J ，Yu X ，Liu Q ，Li A ，Wu Z ，Zeng X ... -  《BMJ Open》

Social inequality in dental caries and changes over time among Indigenous and non-Indigenous Australian children.

This paper describes and compares magnitudes of socioeconomic (SES) inequalities in oral health among Indigenous and non-Indigenous children over a 10-year period. We analysed annual oral health survey data from NSW, NT and SA. Data were extracted for time period 1 (2000-2002, N=215,317) and time period 2 (2007-2010, N=34,495). Oral health outcomes were untreated decayed deciduous teeth (dt) and cumulative dental caries experience (dmft). Postcode-level Socioeconomic Index for Areas was used to assess SES. Age standardisation and complex survey weights were used. Indices of socioeconomic inequality in health (Slope Index of Inequality, Relative Index of Inequality, Absolute and Relative Concentration Index) were used to quantify inequality in dental caries and its changes over time. Oral health outcomes deteriorated in both Indigenous and non-Indigenous populations over time. Indigenous children experienced higher levels of disease at both times. Untreated dt increased in both populations. The cummulative disease (dmft) increased at higher rate among children in low-SES areas in both populations. Over time, there was an increase in socioecononomic inequalities in dmft in all children and in dt in non-Indigenous children. Area-level socioeconomic inequality in child oral health has widened due to deterioration in low-SES children.

Ha DH ，Xiangqun J ，Cecilia MG ，Jason A ，Do LG ，Jamieson LM ... -  《-》

Inequalities in Caries Experience Among Mongolian Children.

Chinzorig T ，Aida J ，Cooray U ，Nyamdorj T ，Mashbaljir S ，Osaka K ，Garidkhuu A ... -  《-》

Socially unequal improvements in dental caries levels in Brazilian adolescents between 2003 and 2010.

Although there are numerous reports on socioeconomic inequalities in dental caries, few studies have focused on whether improvements in dental status have been accompanied by changes in socioeconomic inequalities in caries. The objective of this study was to assess whether declines in caries between 2003 and 2010 were associated with reductions in inequalities in dental caries in adolescents. Data on dental caries in adolescents aged 15-19 were used from the Brazilian National Oral Health surveys conducted in 2003 (n = 16 833) and 2010 (n = 5445). The dependent variables were Decayed, Missing and Filled Teeth (DMFT) index and the percentage caries free. Household income and educational level were independent variables. Differences between surveys for DMFT and caries free were calculated, and measurement of inequality was performed using the Slope Index of Inequality (SII) and Relative Index of Inequality (RII). Both DMFT and percentage caries free showed significant differences in absolute (SII) and relative (RII) inequalities between the two surveys for both education and income. The SII for DMFT rose from 0.54 to 2.01 and from 1.44 to 3.67 for income and education, respectively. For caries free, these values were 3.64-19.40 and 5.06-22.93. Regarding to RII, a similar trend has been found. Despite the overall reduction in DMFT and an increase in caries free, there were increases in both income and education-related inequalities in caries in Brazilian adolescents. The findings on caries differ from those for other health conditions in Brazil, where there have been reductions in inequalities.

Roncalli AG ，Sheiham A ，Tsakos G ，Watt RG ... -  《-》