Fixed Expanders

We offer a complete range of fixed expanders to suit your needs and preferences. We still make many Hyraxes (also called RPE’s), but Haas Appliances and what we call Bonded RPE’s have become just as popular.

We have taken advantage of the industry’s evolution and offer a wide variety of screws, wires and auxiliaries. Snap Lock screws are becoming popular with doctors and patients, but the Palex II is still our standard. Single Leg Slim Line screws have moved from being exclusive to a lower arch to added comfort for the upper arch.

The screws come in various sizes so the size that we use will be determined by the expansion you hope to accomplish and the size of the palette. Slim Line screws come in 8 and 12mm (of expansion). The Palex II and Snap Lock Screws come in 8, 10 and 12mm.

For increased functionality, we can add habit attachments to prevent thumb sucking or tongue thrust, hooks for elastics, head gear attachments, springs, cross over wires, and anything else that you may need.

Some doctors prefer a more contoured fit so we adapt wires to each tooth, while other doctors prefer a straighter wire. .036 or .040 are our standard wire sizes.

Our standard might not be your standard, so we work with you to give you exactly what you want. Communication is key, and we pride ourselves on being good communicators.

Fixed Expanders Hyrax


The industry standard for half a century, hyraxes are made with the legs of the screw soldered to two or four molar bands. We smooth down the edges to provide a more comfortable appliance.

Fixed Expanders Haas


The Haas utilizes molar bands, a wire soldered to the bands extended up to the pre-molars or d’’s, and a Schwarz screw embedded in an acrylic palette. The fit is that of a removable expander. For added retention, we solder eyelet springs to the canines that can be cemented into place.

Fixed Expanders Bonded RPE Wire

Bonded RPE, Wire

The Bonded RPE (wire), uses a hyrax screw soldered to a metal framework without bands. An acrylic platform is then poured over the framework and finished down so it only covers the teeth which you can then cement into place.

Fixed Expanders Bonded RPE No Wire

Bonded RPE, No Wire

The Bonded RPE (no wire) uses a Schwarz screw embedded in an acrylic palette with occlusal coverage. No wire or bands are used. The appliance is cemented into place. It is especially useful for patients with allergies to nickel, as we can use a nickel free Schwarz screw.

Fixed Expanders Fixed Lower Expander

Fixed Lower Expander (FLE)

The FLE uses a Slim Line Screw. A special .036 wire (Duraloy) is contoured from the cuspid to the molar band. The screw is soldered either to the molar band or, for better patient comfort, to the wire at the d’’s or pre-molars. Though predominantly for mandibular arches, this design can also be used for maxillary arches, with or without the contoured wire.

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