LAUSR

AIM The aim of this study is to compare the dental and orthopaedic effects of the Leaf Expander with rapid and slow maxillary expanders. MATERIALS AND METHODS The sample comprised 30 patients with a posterior crossbite divided into three groups: the rapid maxillary expander (RME) group (3 m, 7 f), average age 8.9 years; the slow maxillary expander (SME) group (7 m, 3 f) average age 12.2 years; the Leaf Expander (LE) group (7 m, 3 f), average age 7.9 years. Postero-anterior cephalometric studies have been obtained at the beginning of the therapy (T1) and after 9 months (T2). Nasal width, maxillary width, mandibular width, upper permanent molars width have been measured by a calibrated examiner. RESULTS All the measurements increased significantly after the treatment (paired t-test P=0.05). Maxillary average width increased of 4.2 mm (SD 3.6 mm) in RME; + 2.8 mm (SD 2.8 mm) in RSE and +3.6 mm (SD 2.2 mm) in LE group. Upper permanent molars width increased: + 5.4 mm (SD 3.31 mm) in RME; + 5.4 mm (SD 3.3 mm) in SME and + 3.8 mm (SD 2.1 mm) in LE group. No statistical differencesbetween the groups have been found (t-student test P=.05). CONCLUSIONS The effectiveness of the LE in transversal deficiency correction has been confirmed.