An oral epidemiological comparison of Chinese and New Zealand adults in 2 key age groups.

OBJECTIVES: To use recent national survey data to compare dentition status and oral diseases in China and New Zealand (NZ), with a particular focus on differences by sex and education level. METHODS: We undertook secondary analysis of representative data from oral health surveys conducted in 2009 in Sichuan (China) and NZ. Both surveys had an oral examination component and collected detailed demographic data. Socioeconomic position in this analysis was represented by the highest level of education completed. Participants were allocated to 1 of 3 comparable ordinal categories of years of education (primary, middle or tertiary). Analyses used survey weights. RESULTS: The proportion of Chinese who had been educated to only primary level was 3 times higher than that among their NZ counterparts, and the proportion with a tertiary education was correspondingly lower. In the 35-44 age group, the dentate proportions were similar, although the mean number of teeth was higher in China than in NZ. There were substantial differences in dental caries experience, with the mean DMFT in NZ being almost 3 times that observed in China. New Zealanders had more filled teeth, but the prevalence of 1+ missing teeth was lower. Periodontitis was more common in the NZ sample than in the Chinese one, although the extent of bleeding on probing was almost 3 times higher among the latter. For the 65-74 age group, there were significant differences in dentition status, with greater tooth retention among Chinese people. There were also significant differences in dental caries experience, with Chinese 65- to 74-year-olds having more decayed teeth but fewer filled or missing teeth, and lower DMFT scores, on average. Periodontal health was better among the New Zealanders. There were notable differences by sex and education level. CONCLUSIONS: The differences observed in this study provide strong support for using broader sociocultural models of oral health.