Interdental Occlusal Characteristics of the Primary Dentition

Abstract

Objective: To identify the interarch relationship of the primary dentition in Southern Chinese children. Materials: There were 212 study models (with caries-free primary dentition), comprising 116 boys and 96 girls. The mean age was 5.2 years. The sample was selected from a larger group of 947 study models, 498 males and 449 females, obtained during an oral health survey in 1986-1988. Methods: The second primary molar relationship, canine relationship, overjet, overbite, midline, and posterior bite relationship were assessed. Results: Sex differences were found only for the second primary molar relationship and for the primary canine relationship. The majority of boys had either a flush terminal plane relationship or a difference in the molar relationship on each side and a Class II canine relationship. The majority of the girls had a mesial step molar relationship and either a Class I or Class II canine relationship. In addition, the majority of the children showed ideal overjet, deep overbite and coincidental midlines, and almost all had normal posterior bite in the transverse direction.