Occlusion and Tooth/arch Dimensions in the Primary Dentition of Preschool Jordanian Children

Objectives: To assess tooth and arch dimensions, occlusal relationships and the presence of spacing or crowding in primary dentition of Jordanian children.

Study Design: A list of 10 kindergartens was randomly selected in the governate of Irbid, Jordan. A total of 1048 children (2.5-6 years old) with complete primary dentitions were examined for occlusal relationships in three planes, and the presence of spacing or crowding. Of those, study casts were taken for 87 randomly selected 4-5-year-old children (39 girls, 48 boys). Measurements of tooth and arch dimensions were made using electronic digital sliding callipers.

Results: In general, males had larger mesiodistal tooth width and larger arch dimensions. Bilateral mesial step molar relationship was found in 47.7% of children followed by bilateral flush terminal molar relationship in 37% and bilateral distal step in 3.7%. Asymmetric right/left molar relationship was found in 11.6% of children examined. Class I canine relationship was found in 57% of children, followed by Class II canines in 29% and Class III canines in 3.7%. Fifty per cent of children examined had Class I incisors, 24.7% had Class II Division 1, 13.5% had Class II Division 2 and 11.8% showed reversed overjet. Ideal overbite was seen in 44.3% of children, reduced overbite in 21.8%, increased overbite in 28.2% and 5.7% had anterior openbite. Buccal crossbite was seen in 7% of the sample. Generalized spacing was found in 61.8% and 61.1% of children in the upper and lower arches, respectively. Anthropoid spaces were found in 70% of the upper arches and in 51% of the lower arches.

Conclusions: Males had larger tooth/arch dimension than that of females in the primary dentition stage. Mesial step molar relationship was found in 47.7% of the subjects followed by flush terminal molar relationship in 37%. The majority of children examined had spaced primary dentition.