How Long Orthodontics Takes

How long it takes depends mainly on how far and in what way the teeth need to move, not on which appliance you choose. Teeth move through bone at a rate that is physiologically limited, and no appliance speeds that up. Comparing clear aligners with fixed appliances, the literature found that in non-extraction cases there is no significant difference between the two in either treatment time or quality; but in extraction cases fixed appliances performed better on treatment quality, because they control tooth movement more closely. What really determines the duration, then, is your own situation.

更新日期：2026-08-22 資料來源：本頁末列出

First, a myth to dispose of

Changing the appliance does not make teeth move faster

Orthodontics works by applying a light, continuous force to a tooth so that the bone around the root resorbs and rebuilds, which is what allows the tooth to move through it. That process is physiological and has its own pace — applying greater force does not accelerate it and may instead cause problems such as root resorption.

So the question "which method is faster" usually has its answer not in the appliance but in how far the teeth must move, how many of them, and in which direction. Simple mild crowding and a case that needs large spaces closed after extractions are on quite different scales from the outset.

One systematic review compared treatment duration in mild to moderate crowding and concluded that there was no significant difference between clear aligners and fixed appliances (the authors also graded the certainty of the evidence as low). Another review covering 15 trials and 1,084 patients reached a similar result: in non-extraction cases, the two showed no significant difference in either treatment quality or duration.

Three-stage diagram of an upper arch moving from a crowded arrangement into a smooth curve — Orthodontics is the process of moving teeth gradually through the bone that holds them. Illustrative diagram, not an image of any particular patient.

What affects the duration

Same treatment, so why does one person take a year and another three

01

How far and in which direction the teeth must move

Mild crowding needs only small adjustments; closing larger spaces after extractions, or changing the inclination and rotation of teeth, takes appreciably longer. Movement in the vertical direction also generally takes more time than horizontal movement.

02

Whether the problem is skeletal

If the bite problem arises from the relative position of the upper and lower jaws rather than from the alignment of the teeth alone, both the approach and the timescale differ. Children and adolescents who are still growing may leave room for guidance; in adults, other approaches may need to be assessed alongside.

03

Cooperation

The weight of this factor is often underestimated. Clear aligners have to be worn enough hours each day for the teeth to move as planned, and wearing them less puts the schedule straight back; fixed appliances cannot be removed, but the quality of cleaning and keeping to review appointments affect progress just as much.

04

The state of the gums and the mouth

Orthodontics needs healthy periodontal tissue as its foundation. Where there is uncontrolled periodontal inflammation, moving teeth on unstable bony support carries greater risk, so the periodontal condition is normally treated first. The same goes for decay, which is dealt with before treatment begins.

The two approaches

How to choose between clear aligners and fixed appliances

The literature concludes that both can achieve the goals of treatment; the choice should follow the complexity of the case and the patient's cooperation, rather than a simple ranking of one above the other.

	Clear aligners	Fixed appliances
Appearance	Relatively inconspicuous	Visible on the surface of the teeth
Can they be removed	Removable, making eating and cleaning easier	Cannot be removed by the wearer
Dependence on cooperation	High; must be worn enough hours every day	Lower; the force is applied continuously
Control of complex movements	The literature notes more limited control in extraction cases	Performed better on treatment quality in extraction cases
Cleaning	Normal brushing once removed; the aligners themselves also need cleaning	Requires dedicated orthodontic cleaning aids and is harder to do well

The table above is drawn from a systematic review covering 15 trials and 1,084 patients. That study also noted high heterogeneity between the individual studies and relatively short follow-up, so its conclusions remain limited. These are the overall findings of the literature, not this clinic's outcomes; which approach actually suits you must be assessed by a dentist after an examination.

Removing the appliance is not the end: retention is part of the treatment

Once teeth have been moved into their new positions, the surrounding bone and periodontal ligament need time to stabilise again. Until then the teeth tend to drift back, which is why a retainer is needed after treatment finishes.

As for which form of retention is better, and how long it should be worn, there is at present no clear answer. A Cochrane systematic review covering 47 studies and 4,377 participants examined removable against fixed retainers, different materials and different types, and concluded that the certainty of the evidence was low to very low and that no approach could be shown to be superior to any other, noting that more high-quality studies with at least two years of follow-up are needed.

Insufficient evidence does not mean retention can be skipped. It means that no one can currently say which form is better, so the dentist decides according to the type of treatment you had, your original alignment and your risk of relapse — and what you have to do is wear the retainer as instructed.

Comparative diagram of the structure of clear aligners and fixed appliances — The structural differences between the two kinds of appliance. The literature indicates that both can achieve the goals of treatment, and the choice should follow the complexity of the case and the patient's cooperation. Illustrative diagram, not an image of any particular patient.

Before starting

What the assessment usually involves

An orthodontic assessment is more thorough than an ordinary check-up, because what has to be planned is the movement of a whole set of teeth in three dimensions. It generally includes an intraoral examination and impressions (or a digital intraoral scan), a panoramic radiograph and a lateral cephalometric radiograph, used to analyse the relationship between the teeth and the jaws.

The purpose of all this is to answer three questions: whether the problem lies in the alignment of the teeth or in the position of the jaws, whether extractions are needed to create space, and what a workable plan of movement would be. The answers to those three questions also determine roughly how long treatment will take.

It is worth saying that any promise about duration made before the examination is unreliable. The sensible approach is to complete the assessment and then have the dentist set out the expected range and the factors that might affect progress, adjusting during treatment according to how the teeth actually respond.

其他人也問

常見問題

On average, how long do braces take?

There is no average that applies to everyone. The duration depends on how far and in which direction the teeth have to move, whether extractions are needed, whether the problem originates in the jaws, and on cooperation. Only after a full assessment can an expected range be given for your particular situation.

Are clear aligners faster than traditional appliances?

The literature does not support that claim. A systematic review of mild-to-moderate crowding cases found no significant difference in treatment duration between the two; another review covering 15 trials likewise found comparable quality and duration in non-extraction cases, while in extraction cases fixed appliances performed better on treatment quality.

Can adults still have orthodontic treatment?

Yes. The mechanism by which teeth move through bone is not limited by age, and adult orthodontics is common in practice. The difference is that adults no longer have growth potential, so if the problem arises from the relative position of the jaws, the workable options differ from those for children and adolescents and need separate assessment.

Do teeth always have to be extracted?

Not necessarily. Whether extractions are needed depends on how much space the alignment requires, on the lips and facial profile, and on the state of the jaws. Where space is needed but extraction is to be avoided, it may sometimes be gained by other means, though the situations in which that applies are limited. This has to be judged after a full assessment.

Will the teeth shift again after treatment?

There is a tendency for them to, which is why a retainer is needed. After teeth are moved into new positions, the surrounding tissues need time to stabilise. A Cochrane systematic review notes that the evidence is currently insufficient to judge which form of retention is better, so in practice the dentist decides the form and the period according to the individual risk of relapse.

Does orthodontic treatment loosen the teeth?

There is a slight sense of looseness during treatment, which is a normal part of the bone remodelling and generally settles once the movement stops. However, where periodontal disease is already present and not under control, moving teeth on inadequate support carries greater risk, which is why the periodontal condition is confirmed before treatment begins.

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Other pages

Get it clear first, then decide

What the fee is made of, what to watch out for, and what happens at the first visit.

Our dentists

Education, specialist training, professional associations and treatment scope of the four dentists — every item independently verifiable.

The clinic and its equipment

Space, equipment and infection control; the clinic participates in the NHI enhanced infection control program, with official records to verify.

Veneers and aesthetic restoration

How treatment proceeds, long-term survival figures in the literature, and the questions worth asking before deciding.

Gum health and implants

Gums are the foundation of every treatment. Includes coverage details of the NHI Integrated Periodontal Care Program.

Licensed & Registered

Government approval comes before opening

In Taiwan, a dental clinic may only open after it has been approved and registered by the local health authority and issued a practice license under the Medical Care Act, and every practicing dentist must hold a physician certificate issued by the Ministry of Health and Welfare. 君漾美牙醫診所 (JYM Dental Clinic) is a legally established, government-approved medical institution (medical institution code 3701028607), a National Health Insurance contracted clinic (contracted since 2021), and a participant in the NHI Administration's Integrated Periodontal Care Program and Enhanced Infection Control Program for Dental Outpatient Clinics. Every item above can be verified in official public records.

How Long Does Orthodontic Treatment Take?