Abstract
Abstract: The study focused on the evaluation of changes in upper and lower dental arch following rapid palatal expansion (RPE) in mixed dentition and the expansion stability into the permanent dentition. Material: The first sample (HYRAX group) included 31 patients with RPE in mixed dentition.
The second sample (CONTROL group) included 18 patients without any orthodontic therapy during the period monitored. In both samples the changes in upper and lower dental arches were evaluated.
Method: In 3D digitalized models the following parameters were measured: perimeter, intercanine and intermolar width, inclination of first permanent molars in upper and lower arch, and surface of palate cross-section. Measurements took place at three different times in HYRAX group: prior to therapy (T1), after removal of fixed expansion appliance (T2), after the dentition change (T3); and at two times in CONTROL group: mixed dentition period (T1), after the dentition change (T3).
The values measured served for the evaluation of the parameters after expansion, relapse and stability into the permanent dentition.