Oral hygiene and gingival status of Hong Kong pre-school children

Abstract

OBJECTIVES: To study the oral hygiene and periodontal status of pre-school children in Hong Kong. METHOD: Seven kindergartens were selected by stratified sampling according to their geographic location in Hong Kong. Letters were sent to the parents of all grades 2 and 3 children of the selected kindergartens to ask for consent to let their children participate in this survey. The examination was performed in the kindergartens by two calibrated examiners using CPI probes, dental mirrors, and intra-oral LED lights. The buccal and lingual sites of teeth 55, 52, 64, 75, 72 and 84 were selected for assessment of oral hygiene status and gingival health condition by using the Loe and Silness Plaque Index (PI) and the Gingival Index (GI) respectively. About 10% of the children were re-examined to assess inter-examiner reliability. RESULTS: A total of 764 children were invited and 664 were examined, giving a response rate of 86.9%. Their mean age was 5.0±1.0 years. Their mean PI and GI scores were 1.3 and 1.6, respectively. Only two children (0.3%) had healthy gum in all sites and 77% of them had moderate gingival inflammation (bleeding on probing) in at least half of the sites examined. Results of the multi-factor ANOVA analysis showed that their oral hygiene status was significantly associated with the main caretaker and tooth brushing frequency of the child; and that their gingival health condition was significantly associated with the child's main caretaker, tooth brushing frequency, and use of other dental cleaning aids. CONCLUSION: In this sample of Hong Kong preschool children, poor oral hygiene was common and gingival inflammation was found in almost every child.