Used as an alternative to the removable Schwarz appliance, this fixed metal expander provides lateral expansion in the mandibular arch. It is a good option when patient cooperation might be an issue.
A miniaturized version of an RPE screw is placed lingual to the anteriors. Heavy arms extend back from the screw and are soldered to bands on the first molars. Lingual arms of .036 are also soldered to the molar bands and extend forward contacting the lingual of the bicuspids or D's and E's.