You will find removable and stuck retainers. Set retainers are also called bonded retainers and are hooked up to the back of teeth with dental bonding. These are most popular typically for young people who are unlikely to keep up with their retainer with no it getting fixed into position. https://gunnertqjbt.blogtov.com/13382028/not-known-facts-about-orthodontic-products-in-uk