Horizontal Relationship Between Deciduous Dental Arches in Japanese-Brazilian Children

OBJECTIVES: The purpose of this transversal study was to verify the prevalence of the different types of anteroposterior relationship between deciduous dental arches, as well as the possible sexual dimorphism, in 2 to 6 year-old Japanese-Brazilian children. METHODS: The dental relations between deciduous molars and cuspids were visually examined in 310 children (154 males and 156 females) enrolled in 19 kindergartens in São Paulo state (Brazil). The occlusal relationships between deciduous second molars were classified in three types: mesial step, distal step and flush terminal plane. The occlusion between deciduous cuspids was classified in Class I, Class II and Class III. Furthermore, the overjet between deciduous incisors was classified in normal, edge-to-edge, increased and inverted (cross bite).The qui-square test (p<0.05) was used to analyze the sexual dimorphism regarding these dental relations. RESULTS: The statistical analysis revealed absence of sexual dimorphism for the majority of occlusal relationships examined and, therefore, the prevalence was calculated concomitantly for the total sample. As far as it concerns to the deciduous second molars, the results indicated 47.4% for mesial step, 41.3% for flush terminal plane, 5.5% for distal step and 5.8% for asymmetrical cases. The cuspids exhibited Class I relationship in 77.4%, Class II in 6.8% and also the same value for Class III, whereas asymmetrical relations were observed in 9% of the cases. Only Class II relationship between deciduous cuspids revealed sexual dimorphism, presenting 3.9% for the females and 9.7% for the males. Concerning the overjet, it was considered normal in 77.1%, increased in 14.2%, inverted in 7.4% and edge-to-edge in 7.1%. CONCLUSIONS: The majority of Japanese-Brazilian children evaluated presented normal relationship between deciduous dental arches, however the prevalence of Class III relationship was outstanding.