Retainers After Braces Dublin: Why Teeth Move Back and How We Prevent It

By Dr. Susan O’Connell, BA, B.Dent.Sc TCD (Hons), MFDS RCSEd, MSc U.Birm (Research), M.Orth RCSEng — Specialist Orthodontist | Last reviewed: October 2026

The day braces come off, or the last aligner is finished, feels like the end of orthodontic treatment. It is the end of the active phase. What follows — retention — decides whether the result is still there in ten or twenty years. At the Institute of Specialist and Cosmetic Dentistry (ISCD) in Dublin’s IFSC, retention is planned by our specialist orthodontists before treatment starts, not handed over as an afterthought at the end. This guide explains why teeth move after braces, what the published evidence says about the different kinds of retainer, and what we ask of patients — and of the general dentists who look after them afterwards.

Why do teeth move back after braces?

Teeth move after braces because the gum fibres and bone around them need time to reorganise, and because the bite keeps changing slowly throughout adult life, with or without earlier orthodontic treatment.

Two different things are happening, and it helps to separate them. The first is relapse in the strict sense: a tooth that has been moved is held by fibres in the gum that were stretched during treatment, and for a period afterwards those fibres pull it back towards where it started. The second is ordinary ageing. Lower front teeth in particular tend to crowd gradually through adult life, including in people who have never worn a brace. A retainer is there to resist both.

The Cochrane review of retention (Martin and colleagues, 2023) opens with the plain statement that, without a phase of retention after successful orthodontic treatment, teeth tend to return to their initial position. That is the consensus starting point of the specialty rather than a cautious aside.

How likely is it that teeth will move without a retainer?

In the best-known long-term study, only 10% of 31 patients still had clinically acceptable lower front tooth alignment 20 years after their retainers were stopped, and crowding had continued to increase throughout.

That study, by Little, Riedel and Årtun at the University of Washington (American Journal of Orthodontics and Dentofacial Orthopedics, 1988), followed patients treated with the extraction of four premolars, using records taken at the end of treatment and again 10 and 20 years after retention ended. Crowding went on increasing between the 10-year and 20-year records, though more slowly than in the first decade. The authors also reported that cases responded in a diverse and unpredictable way, with no apparent predictors of who would stay straight.

Two caveats belong with those figures. It is a small study of one type of case, treated decades ago, and every patient in it had stopped wearing retainers — so it describes what happens when retention ends, not what happens when it continues. For patients, the practical reading is the second finding more than the first: nobody can tell you in advance that your teeth are the ones that will stay put, which is why we do not offer retention as optional.

What types of retainer are there, and which works best?

There are two families of retainer — a fixed wire bonded behind the front teeth, and removable retainers worn mainly at night — and the evidence comparing them is rated low to very low certainty.

A fixed (bonded) retainer is a thin wire attached to the back of the front teeth, usually from canine to canine. It works without any effort from the patient, but it makes cleaning between those teeth harder and it can come unstuck from a tooth without being noticed. A removable retainer is either a clear, close-fitting plastic tray or a traditional acrylic-and-wire plate. It is easy to clean around, but it only works when it is worn, and it can be lost, cracked or left in a drawer.

The 2023 Cochrane review pooled 47 randomised studies with 4,377 participants. Its authors judged the evidence low to very low certainty, noted that most studies measured outcomes for less than a year, and concluded that firm conclusions could not be drawn about any one approach to retention over another. Within that, the individual trials are still informative. In one, clear removable retainers worn full-time gave no clinically significant benefit in stability over fixed retainers, were associated with better gum health, and were more likely to fail (a risk ratio of 3.42). In another, there was no evidence of a difference in stability between part-time and full-time wear of a traditional removable retainer. The review excluded studies of aligner treatment, so it speaks to retention after braces specifically.

The longest randomised comparison we rely on is the four-year follow-up by Al-Moghrabi and colleagues (American Journal of Orthodontics and Dentofacial Orthopedics, 2018). Among 42 participants, some relapse occurred in both groups, but lower front tooth irregularity was a median 1.64 mm greater in those given removable clear retainers than in those with a fixed retainer. The same study found gum inflammation and raised plaque levels to be common with both types.

In plain terms: a fixed wire appears to hold the lower front teeth somewhat better over years, no retainer prevents all change, and whichever type you have needs to be kept clean and checked.

How do we plan retention at ISCD?

At ISCD we typically prescribe a fixed retainer bonded behind the lower, and often the upper, front teeth together with a removable retainer worn at night, and we discuss this before active treatment begins.

The reasoning follows the evidence above. The bonded wire holds the teeth most prone to late crowding continuously and passively; the removable retainer protects the overall arch form and acts as a safeguard if a bond on the wire fails between check-ups. The combination is a starting point, not a rule. A patient with a history of gum disease, a deep bite that would put the wire in the way of the lower teeth, or difficulty cleaning around a fixed wire may be better served by removable retention alone, and we would rather say so at the planning stage than repair a problem later. Where the gum condition is part of the decision, we can involve our colleagues in periodontics.

The same principles apply after Invisalign treatment as after fixed braces: the appliance that moved the teeth does not change the biology that moves them back. Our guides to Invisalign for crowding and braces for teenagers describe how retention fits at the end of each.

How long do you need to wear retainers?

Retention continues indefinitely: because teeth keep a lifelong tendency to move, there is no date after which a retainer can be stopped without accepting some risk of change.

This is the answer patients least want to hear, and the one we give at the first appointment rather than the last. What changes over time is the burden, not the principle. The wear schedule for a removable retainer is prescribed for the individual case and reviewed; for most people it settles into night-time wear. A fixed retainer stays in place for as long as it remains intact and the teeth and gums around it stay healthy.

A removable retainer also wears out. It should be brought to review appointments so that its fit can be checked, and replaced when it cracks, loosens or no longer seats fully.

What should you do if your teeth have already moved?

If a removable retainer no longer seats fully without force, stop wearing it and have the teeth assessed; forcing a retainer onto teeth that have moved does not reliably move them back.

What can be done depends on how far the teeth have travelled. Slight movement caught early can sometimes be accepted and held where it is with a new retainer. More noticeable movement usually needs a short further course of treatment — aligners or a fixed appliance — before new retainers are made to the corrected position. Where the original treatment was carried out elsewhere, the starting point is the same — a specialist orthodontic assessment — and our article on complex Invisalign cases covers what happens when earlier aligner treatment has not held.

If a fixed retainer feels rough, loose or different to the tongue, treat it as broken until someone has checked it. A wire that has come away from one tooth no longer holds that tooth, and the tooth can drift while the wire still looks intact.

Are retainers included in the cost of braces or Invisalign at ISCD?

Retainers are included when orthodontic treatment at ISCD is completed; replacement retainers are €150 each, or €250 for a pair, and the specialist orthodontic assessment is €150.

Our published orthodontic fees are a specialist orthodontic assessment at €150, fixed metal or ceramic braces at €1,250 to €3,500 per arch, and Invisalign at €2,500 to €3,500 per case. The retainers fitted when your treatment is completed are included in the treatment fee. Replacement retainers after that are €150 each, or €250 for a pair. Our guide to Invisalign costs explains how orthodontic fees are structured more generally.

We do not discount orthodontic treatment and we do not offer free consultations. When comparing quotations between practices, ask each one the same question: which retainers are included, for how long are they reviewed, and what does a replacement cost?

What should referring dentists check at recall?

For referring dentists, the useful recall checks are bond integrity at every tooth on a fixed retainer, calculus and gingival health around the wire, and the fit of any removable retainer the patient brings.

The four-year trial data above are a reminder that gingival inflammation and plaque accumulation were common findings with both fixed and removable retention, so the hygiene visit matters as much as the wire. A single debonded pad is easy to miss; running a probe along each composite pad takes seconds. Where a tooth has visibly moved, the wire has distorted, or a retainer no longer fits, we would rather see the patient early than late.

On completion of orthodontic treatment at ISCD, our discharge letter sets out the retention protocol for the patient, and the referring practice keeps the patient for routine and restorative care throughout. If you would prefer to take over retention reviews yourself, or would prefer that we keep them, tell us at referral. Our referral process for Dublin dentists sets out what to send, and we welcome a phone call to discuss a case first.

Frequently asked questions about retainers after braces in Dublin

How long do I need to wear retainers after braces?
Indefinitely, in some form. Teeth keep a lifelong tendency to move, so retention has no end date. In practice that usually means a fixed wire behind the front teeth, a removable retainer worn at night, or both, with the wear schedule prescribed for your case and reviewed over time.

Is a fixed retainer better than a removable one?
Each has a trade-off. In a four-year follow-up of a randomised trial of 42 patients, lower front teeth stayed better aligned with a fixed retainer than with a removable clear retainer, but some relapse occurred in both groups. A 2023 Cochrane review of 47 studies rated the overall evidence low to very low certainty and could not recommend one approach over another.

Are retainers included in the cost of Invisalign or braces at ISCD?
Yes. Retainers are included when orthodontic treatment at ISCD is completed. Replacement retainers are 150 euro each, or 250 euro for a pair. The specialist orthodontic assessment is 150 euro.

My teeth have moved since my braces came off. What can be done?
Stop wearing a removable retainer that no longer seats fully without force, and have the teeth assessed. Slight movement can sometimes be held where it is with a new retainer; larger movement usually needs a short further course of aligners or fixed braces before new retainers are fitted.

Arranging an assessment

If you are about to start orthodontic treatment and want to understand how the result will be held, if your teeth have moved since earlier treatment, or if you are a dentist with a patient whose retainer has failed, a specialist orthodontic assessment is the place to start.

Institute of Specialist and Cosmetic Dentistry (ISCD)
4 NCI, Lower Mayor Street, IFSC, Dublin, D01 R7W7
Telephone: +353 1 504 2065
Email: info@iscd.ie

Written by Dr. Susan O’Connell, BA, B.Dent.Sc TCD (Hons), MFDS RCSEd, MSc U.Birm (Research), M.Orth RCSEng — Specialist Orthodontist at the Institute of Specialist and Cosmetic Dentistry, Dublin.

References

Martin C, Littlewood SJ, Millett DT, Doubleday B, Bearn D, Worthington HV, Limones A. Retention procedures for stabilising tooth position after treatment with orthodontic braces. Cochrane Database of Systematic Reviews. 2023;5(5):CD002283. doi:10.1002/14651858.CD002283.pub5
Little RM, Riedel RA, Årtun J. An evaluation of changes in mandibular anterior alignment from 10 to 20 years postretention. American Journal of Orthodontics and Dentofacial Orthopedics. 1988;93(5):423–428. doi:10.1016/0889-5406(88)90102-3
Al-Moghrabi D, Johal A, O’Rourke N, Donos N, Pandis N, Gonzales-Marin C, Fleming PS. Effects of fixed vs removable orthodontic retainers on stability and periodontal health: 4-year follow-up of a randomized controlled trial. American Journal of Orthodontics and Dentofacial Orthopedics. 2018;154(2):167–174.e1. doi:10.1016/j.ajodo.2018.01.007