The retention splint is made for patients after they have worn fixed appliances, so the newly created position of teeth is kept in the future. The final phase of orthodontic treatment is called retention phase or maintenance of therapy results. It begins the moment you remove fixed orthodontic appliance and lasts minimum 12 months. It can last indefinitely, depending on the type of irregularity that is treated. Retainers keep the teeth in the corrected position after the therapy, direct teeth into correct occlusion and prevent unwanted tooth movement. Retention units are usually worn at all times during the first year after completion of the treatment in order to finalize the remodeling of the bone and gum. Afterwards they can be worn only at night to maintain the benefits of the therapy. If the retention appliances are not worn as prescribed, even for a very short period of time, the recurrence can occur and the teeth may come back to the unwanted position.