A comparative evaluation of the effect of rapid maxillary expansion on dentoskeletal structures

The aim of this study is to comparatively evaluate the skeletal, dental and soft tissue effects of posterior acrylic splint (PAS) and modified acrylic splint type (MAS) rapid maxillary expansion (RME) devices on growing individuals in mixed and permanent dentition between 9-15 years of age using three-dimensional model analysis and two-dimensional radiographic methods. In this study, lateral cephalometric radiographs, posteroanterior radiographs and orthodontic plaster models that were obtained from the archive of Gazi University Faculty of Dentistry, Department of Orthodontics, were evaluated for 56 patients having Angle Class I, Class II or Class III malocclusion with bilateral maxillary constriction, who did not receive orthodontic treatment before. Our study was divided into two main groups as PAS and MAS Groups according to the type of RME device. In addition, each group was divided into 2 subgroups according to the dentition period as mixed dentition and permanent dentition. The PAS Group divided into two groups as; Group 1; 15 patients (10 girls, 5 boys) in permanent dentition, Group 2; 14 patients (7 girls, 7 boys) in mixed dentition. Similarly, MAS group divided as Group 3; 14 patient(9 girls, 5 boys) in permanent dentition and Group 4; 13 patients (5 girls, 8 boys) in the mixed dentition period. Student's t test, Mann Whitney U and Chi-Square tests were used for statistical analysis and IBM SPSS Statistics program was used for data analysis. Statistically significant expansion was achieved for both device types. Statistically significant differences were found between the PAS and MAS groups in terms of the changes in upper arch depth, upper incisor and upper lip sagital position (p< 0,025 for each). No difference was observed according to dentition periods in both device types. Similar results were obtained.