Dental health status of Hong Kong preschool children

Abstract

Objectives. To describe the dental health status of preschool children in Hong Kong, and to investigate the e!ects of selected socio-demographic factors and oral health–related behaviors on the dental health of the children. Methods. The study population was Chinese preschool children. The sampling frame was kindergartens with an enrolment of 70 children or more, located on Hong Kong Island. Through strati'ed random sampling, 12 kindergartens were selected. All children attending grades 1 and 2 in the kindergartens were invited. Children with parental consent were clinically examined in the kindergartens in March 2007 by one of two calibrated examiners using a disposable mouth-mirror attached to an intraoral LED light and a ball-ended probe. Diagnostic criteria for dental caries followed those recommended by the World Health Organization. A questionnaire on the child’s socio-demographic background and oral health–related behaviors was completed by the parents. Results. A total of 1513 children were invited and 1343 (89%) were examined. Their mean (standard deviation) age was 3.9 (0.7) years and 51% were boys. Around one third (35%) of the children had experienced dental caries. The mean decayed, missing or 'lled teeth (dmft) score was 1.5, increasing from 1.2 at age 3 to 2.0 at age 5 (analysis of variance, P=0.016). Active decay (dt) accounted for 90% of the dmft score. Higher dmft scores were found in children who were born in Mainland China or came from lower socio-economic classes. Children who had poorer dietary or toothbrushing habits also had more dental caries. Conclusion. Prevalence of dental caries among the Hong Kong preschool children was not high but the severity of caries varied with the children’s socio-demographic background, and their dietary and toothbrushing habits.