Early childhood caries of kindergarten children in Hong Kong

Abstract

Objectives: This cross-sectional survey aimed to study early childhood caries (ECC) status of 3 to 5 years old preschool children in Hong Kong.Methods: This study was conducted in 2016 with ethical approval from Independent Review Board. Seven kindergartens were selected using stratified random sampling method and all kindergarten children aged 3 to 5 years old were invited to participate in this survey. A questionnaire about parental oral health knowledge, child's background, child's snacking behaviors and child's oral health related behaviors was completed by parents. Oral examination was conducted by one trained examiner in the kindergarten using disposable dental mirror attached to an intra-oral LED light and CPI probe. Caries experience of the primary teeth was recorded with dmft index using diagnostic criteria recommended by the WHO. The relationship between caries experience and child's background, snacking behaviors and oral health related behaviors was studied by using multiple logistic regression.Results: A total of 1,480 children were invited and 1,206 children (81%) attended the clinical examination. The mean (±SD) age was 4.6±0.8 years. The prevalence of ECC was 44% (35%, 41% and 53% for the 3-, 4- and 5-year-old children, respectively). The mean dmft (±SD) was 1.9±3.3 (1.3±2.8, 1.8±3.2 and 2.5±3.6 for 3-, 4- and 5-year-old children, respectively). Decayed teeth (dt) was the major component and constituted 93% of the dmft index. Logistic regression analysis showed that caries experience was significantly higher in children who were born outside Hong Kong, from a low-income family, had visited a dentist, was cared mainly by grandparents or relatives, brushed teeth with assistance and snacked more than twice daily.Conclusions: Early childhood caries was prevalent among kindergarten children in Hong Kong, and most of the teeth with caries experience were left untreated.