Active mobile appliances include acrylic plate with retentive parts and active elements which exert orthodontic forces on teeth. This appliance enables moving of a tooth or a group of teeth in different directions. Patient may remove and reinsert a mobile retainer into mouth and orthodontic forces are exerted as long as the patient wears the retainer. It is usually worn at night and few hours during a day. Treatment success depends on patient discipline and awareness.
