The Hyrax (Hygenic Rapid Expander) Wire Frame shown above, originally designed as an upper arch rapid palatal expanding appliance, can also be used as a slow expander. Between three main designs (bonded, banded and wire frame), a variety of available screws, and the option of reverse headgear hooks, there is certainly a design to meet any patient’s lateral expansion needs.
Expansion potential with the Hyrax ranges between 10 and 18 millimeters, depending on the screw used. The traditional Hyrax screw expands at least 10 millimeters and is widely used today. The “Super Screw” can be used for expansion of up to 18 millimeters, and the Memory screw offers spring-loaded expansion.