Retainers are the most important part of the orthodontic treatment. Without them, your teeth will move out of alignment and can become crooked again. Retainers must be worn indefinitely as your teeth will continue to move as you get older (this is inevitable!). There are several types of retainers, they can be made from a clear plastic or can be in the form of a wire placed at the back of your teeth. There are advantages and disadvantages to different types of retainers, your orthodontist will be happy to discuss these with you.