An expander is a device which widens the upper arch in patients with inadequate arch width. This appliance corrects the malocclusion, improves nasal breathing, improves facial aesthetics and creates additional space for future tooth eruption/alignment. This is a customized appliance made to fit the patient’s jaw. Periodic adjustments must be made by a parent until an adequate width of the upper jaw has been achieved. An expander usually precludes the need for orthognathic surgery as an adult (see our “Orthognathic Surgery” page for more information).