Caries patterns in primary dentition in 3-, 5- and 7-year-old children: spatial correlation and preventive consequences.

This study aimed to contribute to the descriptive information of oral health status in the primary dentition, especially concerning the distribution and spatial correlation of lesions. Data were obtained from two surveys. In the Signal-Tandmobiel project 4,468 7-year-old children in Flanders (Belgium) were selected by a stratified clustered random sample. In the Tandje de Voorste - Smile for Life (TDV) project, data were obtained from 1,291 3-year-old and 1,315 5-year-old children. The children were examined by trained dentists, using standardized and widely accepted criteria, based on the British Association for the Study of Community Dentistry criteria. At the population level, symmetry in the prevalence of caries experience across the midline was tested at the tooth and tooth surface levels using generalized estimating equations and alternating logistic regression (ALR) approaches. Individual symmetry was tested using an approach described by Hujoel et al. [J Dent Res 1994;73:1575-1580]. Descriptive observations suggested a symmetrical distribution of caries experience at the population level. The null hypothesis of symmetry could not be rejected at a 0.05 level, suggesting that caries experience might be symmetric in the deciduous dentition. Based on the ALR approach, 2 x 2 associations of caries experience at the tooth and surface levels, both in 5- and 7-year-olds, appeared to be strongest for the left-right pairs in the mandible, followed by the left-right pairs in the maxilla. At the individual level the hypothesis of random caries pattern was rejected (p < 0.0001). In conclusion, at the population level the null hypothesis of left-right symmetry could not be rejected, while at the individual level lesions tended to cluster on one side of the mouth.