Prevalence of tooth wear amongst Hong Kong school children

Objectives: To study the prevalence and severity of tooth wear and its association with oral health related habits and socio-demographic factors of children aged 11-12 in Hong Kong. Methods: This survey was conducted in May 2011 with ethics approval (IRB-UW -11-169). Cluster sampling was adopted and children aged 11 to 12 years in primary schools in the three main districts of Hong Kong were selected. Parental consent was sought. The study comprised of a parental questionnaire to study oral health related habits and socio-demographic factors of the children. Tooth wear was assessed by 3 calibrated examiners using the detection criteria used by the UK Dental Health Survey 2003. Results: A total of 253 children participated and 10% (n=26) had no wear on any tooth surfaces examined. The mean number of tooth surfaces with wear was 3.8±3.3 (mean±SD). Only 5 children had tooth wear involving dentine. The mean number of the occlusal surfaces with wear in first molars was positively associated with age (B=0.36, p=0.016) but not with mother's education level, soft drink consumption, citric beverages or gender (p>0.05). Positive association was also found between frequent vitamin C supplement drinks and the number of worn occlusal surfaces of lower molars (B=0.205, p=0.032) and lingual surfaces of lower incisors (B=0.226, p=0.010). Conclusion: According to this survey, tooth wear in 11-12-year-old children in Hong Kong was prevalent but not severe. Frequent vitamin C supplement drinks was associated with the number of worn tooth surfaces in lower first molars and incisors.