Each set of aligners are worn for about two weeks. In order to keep on track, you should only remove them when you are eating, drinking, brushing or flossing. When you move from one set of aligners to the next, your teeth will slowly move until they have reached their final positions. You will visit the orthodontist about once every six weeks so that your progress can be checked. The course of treatment varies by patient but is usually anywhere from 9-15 months. During your treatment, you could have anywhere from 18-30 aligners that will be worn.