The aim of this study was to investigate the effects of Rapid Maxillary Expansion (RME) on teeth and soft tissues. Data that are taken from 30 individuals were used. These were classified into two equal groups. First one was the Expansion group which we applied banded RME and the other one was the Control group. RME was applied to 15 individuals which had bilateral cross-bite. Lateral cephalometric radiographs were taken before treatment, after treatment and after three months of retention. Control group had no transversal narrowness. Lateral cephalometric radiographs were taken at the beginning and at the end of control. We evaluated the individuals firstly in-groups and then the difference between the groups. Finally, there was a significant decrease at distances from upper incisiv to NA line, the angle between mandibular incisor and NB line increased. Also, after RME the distance from the lower lip to the aesthetic line decreased.