ABSTRACT

Besides maxillary transversal deficiency RME is also a method used to increase the arch perimeter in borderline cases. In this study, the mount of expansion and the increase of the arch perimeter were determined following maxillary expansion with the arcylic splint type of device. Study has been done on 20 patients whom were treated with maxillary expansion as part of their treatment planning. The group consisted of 12 female and 8 male patients with ages ranging from 14 to 20. Splint type of RME device which was made of biothermal material was used for the expansion. The mean expansion period was 34.3 days. The study was carried on the photocopies of the pre and post-expansion models. Differences due to expansion were evaluated with Wilcoxon test. Correlation and Multiple regression analysis were used to evaluate the correlation between the expansion models. Differences due to expansion were evaluate the correlation between the expansion of supporting teeth and the arch length and arch perimeter. Significant increases were found in Intercanine width (4.15 mm), interpremolar width (5.95 mm), intermolar width (7.25 mm) and arch perimeter (5.5 mm) due to expansion. Differences of expansion did not show correlation with differences of arch perimeter and arch length.