A palatal expander is an appliance placed in the roof of the mouth to widen the upper dental arch, which allows the arch to be painlessly separated and spread. A treatment used for younger patients. Many times a palatal expander can be used to create a proper alignment of the arches so permanent teeth have room to erupt in a natural position. Often, the use of an arch expander early may eliminate the need for braces later.
A space maintainer is a removable or fixed appliance designed to maintain an existing space. They are usually fitted to children when they have lost baby teeth early. The gap left from losing this tooth needs to be held open for the permanent tooth to erupt in its correct position.