A retainer is a device made of plastic (and possibly metal) that's made to be worn on the top of teeth. Your orthodontist (a special dentist who helps straighten teeth and fix jaw problems) might ask you to wear a retainer if:

• You just had your braces removed. This is the most common reason kids sometimes need retainers, as they help your teeth stay set in their new positions. You’ll probably have to wear your retainer for at least a few months after getting your braces taken off, but it could be longer.
• Your teeth can be straightened without braces. In some cases, braces aren’t needed, and you can just use a retainer to close a gap in your teeth or to move just one tooth. These retainers might need to be worn for at least a year.
• You have a tongue thrust. This is when your tongue sneaks through your teeth when you talk. Special tongue thrust retainers can help train your tongue to go to the roof of your mouth instead of through your teeth.
• You grind your teeth while you sleep. Also called bruxism, this can cause headaches and jaw pain, and it can also hurt your teeth. Special retainers can help keep your teeth from grinding at night.

How long you need to wear your retainer will depend on the reason you need it. Some retainers are worn for months, and some are worn for years. Some retainers are bonded in place and worn all the time, but others are only worn at certain times of day, usually night.

How Do I Get Fitted for a Retainer?

If your orthodontist tells you that you need a retainer, you’ll need to be fitted so that it can be custom-made for your unique mouth. Your orthodontist will use a special chewy substance that will mold itself to the shape of your mouth when you sink your teeth into it. It’s fast, it doesn’t hurt, and it doesn’t taste bad — in fact, you may even get to choose a flavor.

After you've been fitted for the retainer, you usually have to wait about a week to get the real thing. Then, you'll need to get used to talking with your retainer in your mouth (unless you’re only supposed to wear it at night). You may also notice you have more saliva (spit) in the first few days of wearing your new retainer, which is normal.

Wearing the retainer may make your mouth a little sore for the first few days. This is normal, but if your teeth are in a lot of pain, or you’ve been feeling discomfort for a week or more, make sure you see your orthodontist right away.

How Do I Take Care of My Retainer?

Retainers live in your mouth along with bacteria and leftover pieces of food. You should clean your retainer every day, but check with your orthodontist about how to do it. (Some retainers shouldn’t be cleaned with toothpaste.) Your orthodontist will also tell you whether you need to soak your retainer, and what to soak it in.

Whenever you take your retainer out of your mouth, put it in its case. The case protects it. Don’t wrap it in a napkin or paper towel (which could get damaged or thrown out by mistake), and don’t leave it where a pet can get it.

Plastic can warp easily, so don't put it in water, leave it in a hot car, or place it near something hot. Finally, if your retainer has metal wires, make sure not to bend them. For example, flipping the retainer around in your mouth could bend the wires.

Taking good care of your retainer will help it last longer. This is always a good idea because retainers can be expensive!