A long-term evaluation of the mandibular Schwarz appliance and the acrylic splint expander in early mixed dentition patients

摘要: Introduction: The aim of this prospective longitudinal clinical study was to evaluate the short-term and long-term changes in dental-arch dimensions patients treated with either an acrylic splint rapid maxillary expander alone (RME-only) or a combined mandibular removable Schwarz plate (RME-Sz) early mixed dentition, followed later by fixed appliances permanent dentition. Methods: dental casts 27 RME-only were compared those 23 RME-Sz 16 untreated controls (CTRL) constricted arches at 4 times: pretreatment (T1), after expansion but before appliance therapy (T2), (T3), observation (T4). mean ages for groups approximately 9 years T1, 12 T2, 14 T3, 20 T4. Arch width, arch depth, perimeter, molar angulation assessed all subjects times. T1-T2, T2-T3, T3-T4, T1-T4 statistically respect CTRL. Results: Treatment produced significant increases widths led significantly more favorable results than protocol: (1) greater transverse width perimeter long term, (2) uprighting posterior teeth buccally, thus allowing amount that clinically effective correction moderate tooth size-arch size discrepancies. In overall interval, perimeters group 3.8 3.7 mm, respectively, when protocol modest (2.6 mm); average increase (2.0 mm) not significant. Conclusions: protocol.