W-Arch (Lower)
The W-Arch Appliance is used for the expansion of the upper and lower teeth. Unlike the RPE, it does not expand the whole upper arch, but instead widens only the teeth in the arch form. The W-Arch is bonded to the permanent upper molars. It is activated prior to placement and will expand at a gradual rate. The W-Arch is the simplest of the “W” expander design appliances.
