ZeroExpander: Metal-free automatic palatal expansion for special-needs patients.

The aim of this paper is to illustrate a new concept for approaching maxillary expansion in paediatric orthodontics with a metal-free fixed automatic appliance in special-needs patients. The ZeroExpander is a complete CAD-CAT full digital and automatic metal-free fixed device. It is designed to expand the maxilla in a pre-programmed automatic way using deciduous teeth as anchorage. Two cases of growing patients with a narrow upper arch are illustrated to present this innovative system, one in complete deciduous dentition and the second in mixed dentition. Both patients were successfully treated with palatal expansion. In the first case we present the use of PEEK, and in the second one the use of PA12. The ZeroExpander, fabricated using metal-free technopolymers and anchored on deciduous teeth, proved to be comfortable and efficient in treating palatal transverse deficiency, without the need of any compliance, even in young patients who must periodically undergo MRI.