Sucking, chewing, and feeding habits and the development of crossbite: a longitudinal study of girls from birth to 3 years of age.

The prevalence of posterior crossbite among pacifier-sucking girls in Falköping, Sweden, was previously found to be 26%. The aim of this investigation was to follow the development of crossbites in pacifier suckers and to determinate the possibility of reducing the prevalence of crossbite by informing and instructing the parents about sucking habits and reducing the time the child has the pacifier in the mouth. Parents of 60 consecutively born girls belonging to St Olof's health district, Falköping, Sweden, were invited to take part in the study. All parents agreed to participate. Five interviews or examinations of each girl took place from birth until 3 years of age. Fifty-four (90%) of the 60 girls were breast-fed. The mean duration of breast-feeding was 8 months, and 67% of the girls were breast-fed for half a year or more. Forty-three children (72%) developed a pacifier-sucking habit, 6 (10%), a digit-sucking habit, and 11 (18%), no sucking habits. The mean duration of breast-feeding was longer for the nonsuckers (11 months) than for the pacifier- and digit-sucking children (5 months). Of the 39 girls who still had the pacifier habit at 3 years of age, 2 had developed a posterior crossbite. Another girl stopped the habit when a crossbite was registered at the 2 1/2-year examination. At the next appointment, the crossbite had corrected itself spontaneously. One of the 2 girls with crossbite at 3 years of age developed a prenormal occlusion with both anterior and posterior crossbites. For 12 more pacifier suckers, an interfering contact was noted with a forced guidance of the mandible and a midline shift. In all 12 cases, the interfering teeth were primary canines. We conclude that parents should be instructed to reduce the "in the mouth time" of the pacifier. The transverse occlusal relationship in pacifier-sucking children should be evaluated between 2 and 3 years of age. If interfering contacts of the primary canines exist, the parents should be instructed to reduce the pacifier-sucking time.