Oral health and hygiene status of Hong Kong kindergarten children

Abstract

OBJECTIVE: To describe the dental caries situation and oral hygiene status of Hong Kong kindergarten children. METHODS: Study population was Chinese children attending grade 1 in kindergartens in Hong Kong. Ethical approval was obtained. The survey took place in early 2009. Children with parental consent were clinically examined in kindergartens by two calibrated examiners using intra-oral LED lights, mouth-mirrors and CPI probes. Diagnostic criteria for dental caries followed the recommendations by the World Health Organization. Oral hygiene was recorded by the visible plaque index (VPI). A questionnaire on the child's demographic background and oral health related behaviors was completed by the parents. RESULTS: A total of 579 children from 15 kindergartens were invited and 531 children were examined. Response rate was 91.7%. Their mean age was 44 months (SD=4) and 55.6 % of them were boys. Their prevalence of dental caries experience was 28.6%. The mean dmfs score was 1.26, and active decay (ds) accounted for 96.4% of the score. Higher dmfs scores were found in children who had frequent intake of sweet snacks, 3 times or more a day, compared to those who had not (1.1 vs. 2.6, p<0.05). Children in lower socio-economic classes (lower parental education level and lower family income) also had more caries experience. Mean VPI score of the children was 49.7%. Only 1.5% of them had no visible plaque on their teeth, while 42.6% had visible plaque on more than half of their tooth surfaces (VPI>50%). Lower VPI scores were found in children who brushed their teeth more frequently. CONCLUSION: Although the prevalence of dental caries among Hong Kong kindergarten children was not high, their caries experience and oral hygiene status varied with their socio-economic background, and their dietary and tooth brushing habits.