Active Plate (Schwarz)

The Schwarz expansion appliance is a removable appliance designed to expand the upper or lower jaw and to create the needed space for relief of mild crowding or development of permanent teeth.

In which cases is it being used?

The upper Schwarz appliance is usually indicated to:

• expand a narrow upper jaw
• relieve mild crowding
• correct a crossbite
• allow normal development of the mandible

The lower Schwarz appliance is usually indicated:

• for patients with mild to moderate crowding in the lower anterior region and
• in cases with significant lingual tipping of the posterior dentition.

What are the main parts of a Schwarz expansion appliance?

The Upper Schwarz appliance consists of an acrylic plate with a midline expansion screw covering the palate. It is attached to the upper jaw with Adam and/or ball ended clasps.

The Lower Schwarz appliance is a horseshoe-shaped removable appliance that fits along the lingual border of the mandibular dentition.

How to activate the appliance?

The appliance is usually activated once per week, producing 0.20-0.25mm of expansion in the midline of the appliance. Usually, the appliance is expanded for 4-5 months, depending on the degree of incisal crowding, producing about 4-5 mm of arch length anteriorly. To achieve the desired results, the appliance should be worn for 24 hours per day and only removed to brush teeth and to turn the screw.