Rapid maxillary expansion on the permanent teeth versus the deciduous teeth: Comparison of skeletal and dentoalveolar effects by volumetric tomography

Abstract

BackgroundThe aim of this study was to evaluate skeletal and dentoalveolar effects of rapid maxillary expansion (RME) on the permanent and deciduous teeth by means of volumetric tomography. MethodsThe sample included 12 patients with transverse maxillary hypoplasia (6 treated with RME on the permanent first molars, 6 treated with RME on the deciduous second molars) in the mixed-dentition phase. Beginning and postexpansion cone beam computed tomography images were compared for analysis of the skeletal and dentoalveolar effects of the two devices. ResultsRME treatment significantly increased the palatal volume in both groups (by 10.78% with RME on the permanent teeth vs. by 9.89% with RME on the deciduous teeth). Intermolar width increased for both skeletal and dental measurements. First upper molar tipping was greater on the first permanent molars when RME was anchored on the deciduous teeth than when anchored on the permanent teeth (4.02° vs 2.13°). Decompensation of the lower molars was greater in patients treated with RME on the permanent teeth than on the deciduous teeth (4.58° vs. 1.71°). ConclusionsRME treatment significantly increased palatal volume. RME anchored on the permanent teeth determined greater dental intermolar width variation and a significant difference in decompensation of the lower molars. RME anchored on the deciduous teeth was more effective in increasing skeletal intermolar width and inclination of the first molars.