Evaluation of different occlusion and dental arch types in 3 to 5 years old children in Kerman, Iran, 2019: A cross-sectional study

Existence of developmental spaces during the primary dentition period is essential for the permanent dentition period and results in regular eruption of permanent teeth. The wide class of different occlusion and dental arch types during the primary dentition period, based on factors such as race, conducted to research the prevalence of these two occlusion factors in 3 to 5 years old children in Kerman-Iran. 520 caries-free children attending different kindergartens were selected to evaluate occlusion parameters in Kerman City, Iran, 2019. The oral examination of children was performed by a senior dental student using a tongue depressor and in a room with sufficient light. Collected data were analyzed by SPSS software using t-test, chi-squared, and analysis of variance (ANOVA) tests. The significant level less than 0.05 was considered. The children had predominantly open arch and prevalence of occlusion types was 73.4% for mesial step (MS), 10.5% for flush terminal plane (FTP), and 1.4% for distal step (DS), respectively. The statistical analysis explained a significant association between MS occlusion and open arch in the mandible (P = 0.013) and between dental arch types and sex in the maxilla (P = 0.028), so that the boys had a higher prevalence of open arch than the girls. The presence of developmental spaces in both jaws had a significant association with the upper mean age of the children (P = 0.001). The dental arches often had developmental spaces and molar relationship of MS during the primary dentition.