Methods: There were two groups (26 patients) in this study. The first group (FM+RME) consisted of 13 patients (mean age of 11.6 years, 9 female and 4 male) were treated by a Delaire type face mask with bonded acrylic-splint rapid maxillary expander and the second group (FM) consisted of 13 patients (mean age of 10.4 years, 9 female and 4 male) were treated by Delaire type face mask with a bonded acrylic-splint. It was applied a protraction force of 400 to 600 gf to both groups. Once adequate overjet (min 2 mm) was obtained in both application groups, face mask therapy was ended. Cephalometric radiographs were taken at the beginning (T1) and end of treatment (T2). The mean treatment times were 6.8 months and 5.9 months for FM+RME and FM, respectively. The skeletal changes were evaluated on cephalograms. Data were analyzed statistically with paired-t test and ANOVA.
Results: A significant increase in the sagittal growth of the maxilla (SNA angle, A-VR and A-MaxVR length), ANB angle, total, upper and lower anterior face height, midfacial lenght, incisor overjet were seen in both groups. Statistical significance was seen only in the FMA angle in the comparison of two groups (p<0.01). Vertical dimensions of FM+RME group increased more than FM group.
Conclusions: Both appliances are effective in the treatment of Class III malocclusions. However in the patients who have critical bite the clinicians should be careful in using face mask therapy with rapid maxillary expansion because of decreasing in overbite and increasing in vertical dimensions.
*This project is supported by Selcuk University Scientific Research Project.