Dental caries status of preschool children in Hong Kong

Abstract

AIM: To study the dental caries status of preschool children in Hong Kong. METHODS: Seven kindergartens were selected from the list of registered kindergartens by stratified sampling according to their geographic location in Hong Kong. Invitation letters were sent to the parents of all grades 2 and 3 children of the selected kindergartens explaining the aim and procedures of the survey and asking for their consent to let their children participate in this survey. Parental questionnaires were distributed to collect information on socio-economic background and the oral health behavior of the children, and the dental knowledge of their parents. The children with parental consent were examined in the kindergartens by two calibrated examiners with the use of CPI probes, dental mirrors, and intra-oral LED lights. The procedures and criteria for caries diagnosis followed those recommended by the World Health Organization. Caries experience was measured by means of the dmft index. RESULTS: A total of 764 children were invited and 700, aged 4-6 years, were surveyed. The response rate was 92%. More than half (58%) of the children examined had caries experience. The mean dmft scores of the 4-, 5-, and 6-year-old children were 1.9, 2.3, and 2.6 respectively. Most of the decayed teeth (95%) were untreated. Statistically significant correlations were found between caries experience of the child and dental habits, socio-economic background, parental education level and parental dental knowledge. CONCLUSIONS: Early childhood caries is prevalent among preschool children in Hong Kong, affecting more than half of the children. Their caries experience is affected by a number of socio-economic and behavioural factors.