Effect of dummy-sucking on the prevalence of posterior cross-bite in the permanent dentition.

In 1971 a comprehensive health inspection of all 4-year-olds in the County of Skaraborg was carried out. This also included a dental examination, in which the prevalence of cross-bite was related to the child's sucking habit. The aim of the present study was to investigate the development of the transverse relation between the arches in these 4-year-olds up to the age of 16. Among the 4-year-old dummy-suckers, the prevalence of cross-bite was five times as high than among children with no previous sucking-habit. In spite of this fact, it has not been possible in this study to establish a significant correlation between previous dummy-sucking and the development of cross-bite in the permanent dentition.