After the fixed orthodontic therapy is completed, the patient will be given a retainer. A retainer is a device that is worn after the therapy is completed, in order to maintain the teeth to their new position. Wearing the retainer is very important, otherwise the teeth might go back to the position they were in before the start of the therapy. The duration of the wearing of the retainer depends on the patient however, it is recommended for it to be worn as longer as possible. There are fixed and mobile retainers. Fixed retainers are attached on the inner side of the teeth after the therapy, while mobile retainers are removable and worn according to the preference of the patient.