Remarkable factors related to preventing relapse of deciduous anterior crossbite

In pedodontic practice, children with deciduous anterior crossbite are frequently encountered. In treating deciduous anterior crossbite, determining the optimal time to start treatment and predicting the prognosis of treatment are very important. We investigated the pre-treatment morphological characteristics of craniofacial complex and dentition of children with deciduous anterior crossbite who showed favorable prognoses and avoided relapse even after growth and development were completed. The subjects consisted of 7 boys and 12 girls with deciduous anterior crossbite before treatment. The subjects were divided into those without relapse (n = 13) and those with relapse (n = 6) and these two groups were compared using their lateral cephalometric radiographs and study models. The following characteristics were demonstrated in the children without relapse: (1) There was no family history of anterior crossbite. (2) There were no significant differences between two groups in the width or length of mandibular dental arch. (3) Anterior facial height was not longer than the standard value. (4) On angular analysis, the variable with the most conspicuous difference between the non-relapsed prognosis group and relapse group was the NSAr angle (Saddle angle). The value of this angle in the nonrelapsed prognosis group was close to the standard value. This retrospective study indicates that early proactive treatment for deciduous anterior crossbite is considered suitable for children with the above characteristics.