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.