Malocclusion and caries prevalence: is there a connection in the primary and mixed dentitions?

The purpose of this epidemiological cross-sectional study was to determine the prevalence of malocclusion and caries in children and to investigate whether a relationship exists between prevalence of caries and studied malocclusion. The study consisted of 8,864 preschool and schoolchildren with primary dentitions (mean age 4.5 years) and mixed dentitions (mean age 8.9 years). 1997 WHO dental caries criteria were applied to both groups. The existence of an increased caries risk was deducted from the dmft and DMFT indices related to age. Malocclusion in primary and mixed dentitions was classified into seven types. Fifty-seven percent of all children had some form of malocclusion. Prevalence of malocclusion increased and was significantly greater in the mixed dentition sample (p<0.001) than in the primary dentition sample. Seventy-four percent of children with primary dentitions and 23% of children with mixed dentitions had zero dmft and DMFT scores. Mean dmft indices in subjects with primary and mixed dentitions were 1.02 and 1.53, respectively. No positive correlation between prevalence of caries and malocclusion could be established in the sub sample with primary teeth only. However, statistically significant parallelism in prevalence of malocclusion and caries were found for posterior cross-bite (p=0.050) and mandibular overjet (p=0.013) in children with mixed dentitions.