A Cross-sectional Study on Caries among Elementary Schoolchildren in Dalian

[Objectives:] To investigate caries status among elementary schoolchildren at age 7-12-years who were living in Shahekou region of Dalian, China. [Methods:] A cross-sectional study was carried out in May-June 2008, and a total of 26,121 schoolchildren (13,672 boys, 12,449 girls) aged 7 to 12 years were examined for the dental conditions. Dental caries was diagnosed according to the criteria of World Health Organization. The prevalence of dental caries was calculated as the number of children with caries divided by the number of all children examined and expressed as percentage. Severity of dental caries was described by DMFT (Decayed, Missing and Filled Teeth number) index. The data was analyzed by using SPSS11.5 software package. [Results:] The prevalence of dental caries increased from 1.4% in 7-year group to 13.5% in 12-year group among boys, and increased from 2.2% to 19.1% among girls (linear regression, p<0.01). Mean DMFT index also increased from 0.02 at 7 age group to 0.21 at 12 age group among boys, and increased from 0.03 to 0.31 among girls (linear regression, p<0.01). In each age group from 8 to 12 years, both the prevalence of dental caries (chi-square test, p<0.01) and mean DMFT index (independent-samples t-test, p<0.01) in girls were higher than what were observed in boys. [Conclusion:] Both the prevalence of dental caries and mean DMFT index increased in higher grade schoolchildren and were higher in girls. More efficient oral health care would be needed among girls and higher grade pupils in elementary school in Dalian. Further epidemiological investigations are necessary to determine the causes of increased prevalence and mean DMFT index among these schoolchildren.

The Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.