Clear retainers

Teeth move back because the gum fibres and bone around them keep a memory of their old positions, and because teeth keep drifting slowly throughout life. The bone needs months to settle around the new positions, and the stretched gum fibres take even longer to adapt.

Rotated teeth are especially likely to turn back, closed gaps to reopen and lower front teeth to crowd again. These are the movements retainers are designed to hold.

Even people who never had treatment see their teeth shift over the years, most often as crowding of the lower front teeth. A retainer protects the result of treatment from both the relapse and that natural drift.

An aligner moves teeth; a retainer holds them still. Both are clear trays made from a scan of your teeth, but an aligner is shaped slightly differently from your current teeth so it pushes them, while a retainer is made to fit your finished teeth exactly.

Retainers are usually made from a slightly sturdier material than aligners, because they are worn for much longer, while each aligner is worn for only about a week.

Because they look alike, people sometimes keep wearing their last aligner as a retainer. That can work for a short time, but an aligner is not designed to last for years and will wear, crack and stop holding the teeth properly.

Neither is better for everyone. A fixed retainer is always in place, so it does not depend on you remembering it, but it usually holds only the front teeth and is harder to clean around. A retainer holds every tooth it covers and is easy to clean, but it only works when worn.

Many clinicians use both for cases that are prone to relapse, such as closed front gaps and corrected rotations: a fixed wire behind the front teeth plus a retainer at night.

A fixed wire can break or come unstuck at one tooth without you noticing, letting that tooth move. If you have one, ask for it to be checked at every dental visit.

Get a replacement as soon as possible, because teeth can start moving within weeks without a retainer. If your scan is on file and your teeth have not moved, a new retainer can be made from it; if they have moved, a new scan is needed and sometimes a short correction first.

Until the replacement arrives, wear your last aligner at night if you still have it and it fits. That gives the teeth some support in the meantime.

Most retainers are lost at meal times, wrapped in a napkin and thrown away. Keeping the case with you is the simplest way to avoid it.

Clear retainers usually need replacing every year or two, sooner if they crack, warp, cloud or stop fitting snugly. How long one lasts depends on how carefully it is cleaned and stored, and on whether you grind your teeth at night.

Grinding wears through retainers faster, sometimes making small holes over the back teeth. If that happens, tell us, because the retainer is also protecting your teeth from the grinding.

Keeping your digital scan on file makes replacements simpler, as long as your teeth have stayed in position.

Retainers can cause a slight lisp for the first day or two while your tongue adjusts, but it usually fades quickly. Because they are thin and follow the shape of the teeth closely, most people speak normally with them very soon.

Wire and acrylic retainers, which cover the roof of the mouth, tend to affect speech more at first. Fixed wires behind the teeth rarely affect speech at all.

Yes, usually. If you had braces or aligners elsewhere and need a new or replacement retainer, a clinician first checks that your teeth are still in a good position and your gums are healthy, then your teeth are scanned so a retainer can be made to fit.

If your teeth have already moved since treatment, a retainer made now would hold them in their shifted position. In that case, the clinician may suggest a short course of aligners to bring them back first, then a retainer.

Bring any records from your previous treatment if you have them. They help show how far the teeth have moved.

Teeth can start to move within weeks of stopping a retainer, especially in the first months after treatment, when the bone and gum fibres are still settling. Later on, movement is usually slower, but it does not stop entirely.

The first sign is often a retainer that feels tight when you put it back in after a break. That tightness is the retainer pushing the teeth back to where they should be, which is exactly why wearing it again quickly matters.

Movement is gradual, so many people do not notice it in the mirror until a gap reopens or the lower front teeth begin to overlap again.

Yes, and a retainer also gives the teeth some protection from night time grinding. The catch is that grinding wears retainers out faster, sometimes making holes over the back teeth within months.

If you notice thinning or holes, or wake up with sore jaw muscles, tell us. Grinding can be managed with a retainer made from a tougher material or with a separate night guard, and the clinician will suggest which suits you.

Contact a dentist promptly and, if you have one, wear your removable retainer full time until the fixed wire is repaired. A broken or loose wire stops holding the tooth it was attached to, and that tooth can move quickly.

Run your tongue along the back of your front teeth occasionally: if you feel a rough spot, a sharp end or a wire that moves, something has come unstuck. Do not try to glue or bend it yourself.

If the wire has been off for a while and the teeth have shifted, a short course of aligners may be needed before a new wire is fitted.

A clear retainer covers the biting surfaces, so while you wear it your teeth meet on plastic rather than on each other. This does not change your bite, but in the weeks after treatment the teeth naturally settle into a slightly firmer contact when the retainer is out, which is normal.

If your bite feels uneven when the retainer is out, or one tooth seems to hit first, mention it at your next check. The clinician can see whether the teeth are settling normally.

A new retainer feels snug, and for a day or two you may notice it when you speak or swallow. Because it is made to fit your finished teeth exactly, it should not cause pressure the way a new aligner does, unless your teeth have already started to move.

If you have just finished aligners, it will feel familiar: a thin, close fitting tray. If you had braces, the smooth feel of a clear tray against the teeth is usually a welcome change from brackets.

A sharp edge or a sore spot on the gum is not normal. A rough edge can be smoothed quickly, so let us know.

No. Boiling water, dishwashers and very hot soaks will warp a clear retainer so it no longer fits your teeth. Clean it with cool or lukewarm water, a soft toothbrush and, occasionally, a cleaning tablet made for retainers.

A warped retainer can look normal but hold the teeth unevenly or not seat fully. If your retainer suddenly fits differently after cleaning, heat is the most likely cause, and it should be replaced.

Yes. Retention is needed after any straightening, whether it was done with braces or aligners, because the reasons teeth move back are the same. Braces patients are often given a fixed wire as well as a removable retainer.

Many adults who come to us for aligners had braces as teenagers and were given a retainer they stopped wearing. Their teeth are the clearest evidence of why the habit matters.

Teenagers need retainers at least as long as adults, and often benefit from wearing them carefully through the late teens, because the jaws are still finishing their growth and teeth can shift as they do.

The challenge with teenagers is consistency. A retainer left in a school bag does nothing, so parents often help by making it part of the bedtime routine. Our parents' guide to clear aligners for teens covers what to watch for during and after treatment.

Take your retainer and its case with you and keep wearing it at night, because a week or two away is long enough for teeth to start moving. Pack it in your hand luggage, not a suitcase that could be delayed or lost.

If you live abroad and lose a retainer, tell us. Where your scan is on file and your teeth have not moved, a replacement can be made in our laboratory in Pakistan and sent to you.