A retainer is a dental device that helps keep your teeth in their new positions after wearing braces. Once your braces are removed, your teeth can shift back to their original places, so a retainer is essential for maintaining your smile. It is usually made of plastic and metal and is custom-fitted to your mouth, ensuring comfort and effectiveness. There are two main types of retainers: fixed retainers, which are bonded to the back of your teeth, and removable retainers, which you can take out when eating or cleaning. Your orthodontist will guide you on how long to wear your retainer each day to keep your teeth aligned.