The clinical evaluation of compact RPE and MPES screws used in rapid maxillary expansion

ABSTRACTThe Clinical Evaluation of ?Compact RPE? and?MPES? Screws used in Rapid Maxillary ExpansionThe aim of this study was to compare the skeletal and dentoalveolar effectsof ?Compact RPE? and ?MPES? screws. The study group consisted of 30 patientswho need rapid maxillary expansion. ?Compact RPE? screw was applied to 14subjects (mean 11,7±1,8 years) and ?MPES? screw was applied to 16 subjects(mean 12,2±1,4 years). In order to measure changes, orthodontic casts, lateral andPA cephalograms and upper occlusal radiograps were taken before treatment ,after expansion and at the end of three months after expansion.The expansion was achieved in 19,6±4,9 and 23,9±8 days with compactand memory screws, respectively.The palatal plane and maxilla moved downward in CRV group duringthe expansion period.CRV group showed more distinct changes for posteriorrotation of mandible, extrusion of upper incisor and upper molar and increases ofupper and lower face heights when compared with MPES group.Maxillary width and nasal width increased significantly during expansionperiod and didn?t change during stabilization period.U6-6, U5-5, U4-4, U3-3 distances increased significantly during expansionperiod in both groups. n this period the distopalatal rotation of upper first molarswere significant for MPES group.The results of this study revealed that both screws have advantages anddisadvantages so each screw can be used dependent on the priority of orthodontist.Key Words: RME, Midpalatal suture, Posterior crossbite, Maxillary transversediscrepancy, Palatal vaultxi