After completing orthodontic treatment, there is an important final stage, which is the retention phase to stabilize the teeth. Dentists recommend patients to wear retainers after the completion of orthodontic treatment. This is because there is a chance that the teeth may relapse or shift after orthodontic treatment, so it is necessary to wear retainers to reduce the possibility of teeth shifting. In the past, many people have experienced tooth shifting because they did not wear retainers, and as a result, they needed to undergo orthodontic treatment again. Therefore, wearing retainers is essential.