One day in the not-too-distant future, your braces will come off. In a few moments, you'll be free of bands and brackets, able to eat what you want and run your tongue over smooth, clean teeth. But, even on this happy occasion, please remember that you're not quite done with orthodontic treatment yet: The next phase, called retention, is just beginning.

Retention is a critical follow-through stage that typically involves wearing an orthodontic appliance called a retainer. Several different kinds of retainers are available, all of which are custom-made.

But if your teeth are straight now, why do you need a retainer at all? Simply put, it's because if you don't wear one, your teeth will start moving right back to where they were!

Teeth aren't set rigidly in the jawbone — instead, they're held in place by a network of fibers called the periodontal ligaments. After they have being moved, it takes several months for the periodontal ligament to adjust to the new position. So if you want to keep that new smile — and not waste all the time, effort, and money it took to get it — it's essential to wear your retainer as directed.

Being fitted for a retainer usually happens on the same day your braces are removed. After your teeth are thoroughly cleaned, another set of X-rays and/or bite impressions may be taken to check how well your braces worked and to see how much your wisdom teeth have developed. Then, a retainer will be prepared for you.

There are three basic types of retainers available today; each works best in particular situations. The most common is the so-called “Hawley” retainer — a thin, tongue-shaped piece of acrylic molded to fit your mouth, with a wire that holds your teeth in position. The Hawley retainer is simple, durable and easily removed. It's even possible to personalize it by choosing different colors and designs for the plastic arch.

Another popular style of retainer is the clear aligner-type, which looks similar to the Invisalign® tray system. These retainers are custom-made of thin, transparent plastic designed to fit precisely over your teeth. Their main advantage is that they're invisible, with no wire to show. These retainers are also easy to remove, but they may be somewhat less durable than the Hawleys. They aren't recommended for patients with certain conditions, like teeth grinding.

Finally, fixed retainers may be an option for some people, especially on the lower front teeth. As their name implies, they aren't removable by the wearer — but they aren't visible either. Like lingual braces, this system uses a wire which is bonded to the tongue side of the teeth. It may remain in place for months, or longer. This type of retainer is sometimes recommended when there's a high risk that teeth could revert to their former position.