Removable appliances are devices which are not cemented to the teeth. During the treatment the patient can only remove it in a case strictly determined by the dentist.
These appliances are often used in juvenile patients.
In this type of appliances there are so-called mechanical devices (with a screw) which used early in life of a child, are used to expand the bones.
Others include, e.g., so-called functional appliances which, when applied in an appropriate developmental age of a child, can cure a defect of distoclusion.