RESUMO
Based on the carried out studies, the prevalence of dental caries in preschool children is high and ranges from 31.64 to 83.7 percents in Iran. The dmft criterion is not able to compute the impact of neighboring teeth on caries status of a tooth in deciduous teeth. The purpose of this study was to investigate the above issue in a sample of 3-5 years old children in Tehran during 2008-2009. In this cross-sectional study, a group of 400, 3-5 years old children who lived in Tehran and referred to Pediatric Dentistry Department of the Dentistry Faculty of Tehran University of Medical Sciences, Iran, for treatment of their deciduous teeth were investigated The demographic variables and mouth health cares data were collected by a questionnaire and the caries status of deciduous teeth were diagnosed by standard methods. The caries statuses were considered as spatially correlated binary data. The auto logistic regression model was implemented for inspecting the association of a tooth and its neighboring teeth which consists of two adjacent teeth and the opponent tooth. The effects of factors were tested using z-score. The fitted model and the computed criteria showed that there was a strong dependency between caries statuses of a tooth and its three neighbors [including the two adjacent and the vertically opponent teeth] [p=0.0001]. Also the effect of spatial auto covariate which is equivalent to the sum of statuses of nearest neighbors of a tooth is highly significant. Furthermore, the effects of local variables such as jaw and posterior-anterior positions were also highly significant [p=0.0001]. In deciduous teeth, the three nearest neighbors have a high effect on a tooth. As a result, the teeth in maxilla and posterior locations are decayed sooner than the other ones. These findings may be considered in preventive programs of health of mouth and tooth in children