Abstract

Design This was an Australian case-control study.Case-control selectionCases were recruited from children referred for dental treatment under general anaesthesia at free public hospitals in eight health service districts in the state of Queensland, Australia [early childhood caries (ECC) public cases], and three private specialist paediatric dental clinics (ECC private cases). Controls were selected from a full list of all childcare facilities in the area using a selection ratio of one in seven children. As dental health status of the children was unknown prior to recruitment, a subgroup of 62 children with ECC was recruited in the control cohort (ECC childcare) and formed the third source of ECC cases.AscertainmentThe teeth of children in dental clinics or childcare facilities were examined using lighting from an examiner's head-lamp, with the child placed on the laps of the mother and examiner. A child was considered to have ECC if at least one cavity was present. Caries was charted using the World Health Organization oral health survey basic methods criteria 1 and enamel hypoplasia using the modified Developmental Defects of Enamel index. Presence of Streptococcus mutans was also assessed. Mothers were interviewed and screened to determine their social, medical and dental histories; dental caries experience; absence or presence of plaque and gingival inflammation; and presence of S. mutans. Validated questionnaires were used to obtain social, medical, dental, dietary and toothbrushing histories of the mothers.Data analysisGroup comparisons of continuous variables (such as age and birthweight) were compared for statistical significance using analysis of variance. Categorical variables were compared for statistical difference across groups using contingency X 2 tests together with multinomial logistic regression modelling.ResultsA large proportion of children tested positive for S. mutans if their mothers also tested positive. A common risk indicator found in ECC children from childcare facilities and public hospitals was visible plaque [odds ratio (OR), 4.1; 95% confidence interval (CI), 1.0-15.9; and OR, 8.7; 95% CI, 2.3-32.9, respectively). Compared with ECC-free controls, the risk indicators specific to childcare cases were enamel hypoplasia (OR, 4.2; 95% CI, 1.0-18.3), difficulty in cleaning the child's teeth (OR 6.6; 95% CI, 2.2-19.8), presence of S. mutans (OR, 4.8; 95% CI, 0.7-32.6), sweetened drinks (OR, 4.0; 95% CI, 1.2-13.6) and maternal anxiety (OR, 5.1; 95% CI, 1.1-25.0). Risk indicators specific to public hospital cases were presence of S. mutans in the child (OR, 7.7; 95% CI, 1.3-44.6) or mother (OR, 8.1; 95% CI, 0.9-72.4), ethnicity (OR, 5.6; 95% CI, 1.4-22.1), and access of mother to pension or healthcare card (OR, 20.5; 95% CI, 3.5-119.9). By contrast, a history of chronic ear infections was found to be protective for ECC in childcare children (OR, 0.28; 95% CI, 0.09-0.82).ConclusionsThis case-control study showed that children of different socioeconomic backgrounds who have ECC share the common risk indicators of visible plaque, consumption of sugary snacks and presence of S. mutans. Additional risk indicators in children from childcare facilities were enamel hypoplasia, difficulty in cleaning the child's teeth, sweetened drinks and maternal anxiety, whereas ethnicity and mothers' access to pension or healthcare cards were specific to the public hospital cases. © EBD 2009.