Aim: to present a new appliance and evaluate the dental and bone effects of slow maxillary expansion, with low forces, in a sample of growing patients with transversal maxillary deficiency. Materials and method: the studies presented explain the biomechanics of the Leaf Expander appliance. In the studies, the autors have included 15 patients treated with Leaf Expander® were included (6 male, 9 female) with an average age of 7.4. Digital models were made at the beginning of the therapy (T1), and at the end of expansion (T2). Five distance parameters were measured: 1) between the first upper permanent molars; 2) between the upper second deciduous molars; 3) between the upper canine cusps; 4) between the lower molars and; 5) distance of the lower canine cusps. For 5 patients, with loss of space for upper cusps, a cone beam computed tomography (CTBC) was performed at the beginning of the therapy (T1) and after expansion (T2). Three parameters were measured: 1) nasal width; 2) basal bone and; 3) intermolar diameter at II deciduous molars Results: the studies presented and discussed by the autors demonstrate that in all the patients (100%) the complete correction of posterior crossbite has been achieved in 4 monts, on average. Significant increases in the dental and skeletal transversal diameters were obtained. Increases were also obtained about anterior mandibular arch (+ 1mm). Conclusions: this research confirms the soundness of Leaf Expander® appliance in the transversal deficiency correction with a both dental-alveolar and skeletal action in the treatment of growing patients.
(Rev Esp Ortod. 2018;48(2):053-061)