Schwarz Expander

The Schwarz removable expander is designed for mid-line arch widening and can be used on either the upper or lower arch. It typically features a wire frame configuration consisting of a cuspid-to-cuspid labial bow, Adams clasps on the first molars, and additional ball or arrow clasps at the premolars.

Fan Schwarz Expander

Similar to the standard Schwarz expander, the Fan Schwarz incorporates a hinged screw to primarily widen the anterior region while maintaining the existing molar width.

Transverse Expander

The Transverse expander is essentially a Schwarz expander without the labial bow (as shown with buccal tube clasps). Retention is typically achieved with two pairs of Adams clasps, positioned on the first molar and first bicuspid, similar to a sagittal appliance.Sagittal Expander

Sagittal Appliance

For situations where a removable distalizing appliance is preferred, the Sagittal appliance provides an effective option. These appliances are particularly useful for regaining lost arch length in either the anterior or posterior segments of the dental arch. Retention is achieved using Adams clasps, which engage on the first bicuspids and first molars, ensuring a secure and stable fit. Maxillary Sagittal appliances typically incorporate twin expansion screws placed mesial to the first molars. To facilitate expansion, the appliance is divided into three distinct sections. This segmentation allows for controlled and differential expansion as needed. In contrast, mandibular Sagittal appliances position the expansion screws in the cuspid/bicuspid region. Additional features may include springs designed to reposition the canines as space becomes available, further enhancing the treatment outcome. Moreover, posterior acrylic coverage may be incorporated to reduce or eliminate occlusal contact between the maxillary and mandibular teeth, minimizing interference during treatment. This acrylic coverage helps prevent undesirable tooth movements and ensures that the distalization proceeds smoothly.

For added transverse expansion, a third mid-line screw can be incorporated into the sagittal expander.

Bertoni Expander

The Bertoni expander offers 3-way expansion through a different mechanism compared to the sagittal expander. Its Bertoni screw allows independent activation in three directions: anterior advancement and independent widening of each side. The wire framework mirrors the Schwarz, featuring a cuspid-to-cuspid labial bow, Adams clasps on the first molars, and ball or arrow clasps at the bicuspids or premolars.