Objectives: The aim of the study was to develop a mathematical model for the visualization and evaluation of transversal palatal soft tissue changes; and to carry out a statistical evaluation of the changes in vertical and sagittal dimensions after rapid maxillary expansion treatment.
Material and Methods: 33 Caucasian children with posterior crossbite, 10 boys and 23 girls, aged 7 to 10 years (median 8 years 8 months) were treated with tooth-borne Haas type expander. Dental casts were digitalized by scanner and on the basis of quantitative mesh shape CPD-DCA analysis, coloured morphometrical maps were created. The statistical significance of individual vertex displacements was calculated by performing Hotelling’s T2 paired test. To determine the significance of the vertical and sagittal profile changes, the paired t-test and Wilcoxon signed rank test were carried out in 20 patients
Results: Visualization of the palatal soft tissue widening showed it to be greatest in the areas of the second deciduous and first permanent molars with maximum of 0.75 mm for each palatal side. Hotelling’s T2 paired test showed significant differences of p<0.01 in transversal width dimension. Cephalometric measurements of the changes to vertical and sagittal dimensions were statistically evaluated using the Wilcoxon and paired t-tests, and were shown to have insignificant values of p>0.05.
Conclusion: The expansion appliance in children resolved the crossbite and led to palatal widening, which was clearly visualized by creating mathematical morphometric models. The cephalometric measurements carried out did not reveal statistically significant relevance in changes to facial vertical or sagittal dimensions.