Contemporary Ortho Appliances Practice Test 2026 – The All-in-One Guide to Master Your Certification!

Expanding the upper jaw relies on devices that apply lateral forces to widen the palate. The Hyrax is a fixed rapid palatal expander attached to the upper molars with bands and a central screw; when the screw is activated, it pushes the two halves of the maxilla apart, producing rapid skeletal widening at the midpalatal suture. The Schwarz appliance is removable and consists of an acrylic palatal plate with a midline screw that the patient or clinician activates to gradually widen the arch, with the appliance worn in the mouth and removed for cleaning.

Rapid palatal expansion is indicated for transverse maxillary deficiency in growing patients, aiming to correct a narrow upper jaw and related crossbite by achieving skeletal widening rather than just dental tipping. In adults, expansion is less skeletal and may require additional procedures.