Fixed Braces vs Invisalign: How Orthodontists Choose the Right Option

Fixed braces vs Invisalign? This is a clinical decision, rather than a matter of personal preference. An orthodontist chooses between them based on the type and complexity of tooth movement required, your bite, and, where aligners are being considered, whether you can wear them consistently.

Interest in straightening teeth has grown across London and the UK, and both systems are designed to straighten teeth and improve the bite, but they do so in different ways.

Every orthodontic consultation starts with diagnosis rather than a preferred product. This aligns with the General Dental Council and the British Orthodontic Society, which treat orthodontic treatment as a prescribed dental procedure rather than a cosmetic extra.

Braces or Invisalign: which is better?

Neither is inherently better. Invisalign can produce excellent results when a case is well suited to aligners, and the patient wears them consistently. Fixed braces, however, can offer greater control for some complex tooth movements. The right choice depends on the individual diagnosis.

How braces and Invisalign actually move teeth

Both systems move teeth by applying controlled forces that encourage the bone around the roots to remodel. The difference lies in how each system delivers that force.

Fixed braces use small brackets bonded to the front of each tooth, connected by an archwire and held in place with ligatures or self-ligating clips. Because the brackets and wires stay on the teeth day and night, fixed braces use pressure that works around the clock without any input from you. At Hampstead Orthodontic Practice, we offer several styles, including ceramic braces such as Symetri Clear and hidden lingual braces such as Incognito for patients who’d rather have their brackets out of sight.

Invisalign works differently: a series of custom-made clear aligners shifts the crown and root of each tooth in small stages, with patients typically moving to a new aligner every one to two weeks, according to the schedule their orthodontist sets. Many cases also need small tooth-coloured attachments and elastics for grip on the trickier rotations. Each stage is mapped out in advance using hi-tech software and 3D scans taken with a device such as an iTero Intraoral Digital Scanner.

How does an orthodontist decide between braces or Invisalign?

This is done by assessing the bite objectively: how the upper and lower teeth meet, the degree of any skeletal discrepancy, the angle of the tooth roots, and which direction each tooth needs to travel.

That assessment covers:

1. Malocclusion type, such as a deep bite, open bite, crossbite, or a pronounced overjet or underbite.
2. Dental crowding and how much space is available or needs creating.
3. Jaw alignment and whether premolar extractions would help.

Mild to moderate spacing, relapse after teenage treatment, and minor cosmetic alignment of the front teeth are often well suited to clear aligners. But some complex cases may be more predictable with fixed appliances. Severe skeletal discrepancies, impacted canines, large extraction spaces and significant bodily root movement may require the mechanical control that brackets and wires provide, although the right approach always depends on the individual diagnosis and treatment plan.

Orthodontists may also refer to the Index of Orthodontic Treatment Need (IOTN). However, it isn't a universal scale for deciding between Invisalign versus fixed braces; that decision rests on the specific tooth movements required. At our practice, a full diagnostic record, including digital impressions, clinical photography, and panoramic or CBCT X-rays where needed, is taken before any treatment option is proposed.

Are fixed braces more effective than Invisalign?

There’s no simple yes or no answer. A 2026 systematic review published in International Orthodontics found mixed results across different types of tooth movement. Clear aligners and fixed appliances showed mixed results for several movements, while the limited evidence suggested that fixed appliances may offer better control of torque and rotation. The authors were clear that this evidence is still limited and called for further research.

The difference becomes more important when treatment involves complex tooth movements rather than straightforward alignment. When a tooth doesn’t track as the digital plan predicted, especially with vertical movement or a stubborn rotated canine, an orthodontist may switch a patient from aligners to fixed brackets partway through treatment.

One retrospective study of 500 Invisalign patients across two US orthodontic practices found that 17.2% (roughly one in six) switched to fixed braces to complete their treatment. The study concluded that patients should have a reasonable expectation that fixed braces may sometimes be needed to complete treatment.

So while Invisalign may still be the right call for most patients, for cases involving complex tooth movement, braces could give the orthodontist more direct mechanical control over the result.

Braces or aligners: which is better for your daily life?

Invisalign gives you a discreet option and means you can remove the aligners when you eat, but the results depend on how consistently you wear aligners. Fixed braces remove that responsibility, because they work all day without any decision from you.

One of the important things to know before treatment is that clear aligners need to be worn for 20 to 22 hours a day, taken out only to eat, drink anything but water, and clean your teeth. If they aren’t worn for the recommended hours a day, treatment can take longer or need extra refinement trays partway through.

Fixed brackets don’t carry that risk. And while traditional braces can feel more noticeable at first, there’s nothing to remove and nothing to forget to put back in. Lifestyle and reliability matter here, too: For example, Invisalign Teen ^[a]includes features designed to help monitor compliance, which can suit a conscientious teenager well, while fixed braces may offer more reassurance for a busy or forgetful patient of any age.

Daily practicalities: diet, hygiene and comfort

Clear aligners make brushing and flossing straightforward and place no limits on what you eat, while fixed braces need more careful plaque control and a few food changes to protect the brackets and wires.

Aligners come out at mealtimes, so there’s nothing to avoid. Fixed braces are different: crusty bread, toffee and popcorn can debond a bracket or bend a wire, so they’re best avoided for the duration of treatment. The same contrast applies to hygiene: aligner wearers brush and floss much as they always have, while fixed brace wearers need interdental brushes or floss threaders, along with a fluoride mouthwash, to keep plaque, gum inflammation, and white spot marks on the enamel under control.

Aligners tend to feel smoother from day one, while new brackets can rub the cheeks and lips until orthodontic wax and time settle things down. So Invisalign and braces each carry their own pros and cons, and neither wins on every count.

Invisalign vs metal braces: treatment time and cost in London

Treatment speed depends mostly on your biology and case complexity, not on the appliance you choose.

• Simple alignment cases: often around 6 to 12 months.
• More comprehensive bite correction: can take 12 to 24 months or longer.

Your orthodontist should give you an estimated timeframe based on your individual treatment plan once your diagnostic records are complete. Regarding the cost of Invisalign and the cost of metal braces, both depend on case complexity, treatment duration, and the type of appliance used.

At Hampstead Orthodontic Practice, we offer interest-free monthly patient finance, so bespoke private treatment doesn’t need to be paid for in one go. Note that NHS orthodontic treatment is only available to under-18s who meet the required clinical criteria, and isn’t generally available to adults. This is why most adults in London seeking straighter teeth choose private orthodontics.

Retention and choosing your path

Whichever you choose, fixed braces or Invisalign, you’ll need a retention plan afterwards, and your first consultation with a specialist is what actually decides which path suits you.

Teeth naturally tend to move over time, so most patients need to keep wearing retainers to maintain the result, whether you were treated with clear aligners or fixed braces. Your orthodontist will recommend the type and wearing schedule that suits you, whether that’s a removable retainer, a fixed wire, or both.

You don’t need to arrive with a diagnosis already worked out. An experienced orthodontist will assess your bite and give you an honest recommendation, built around what your teeth actually need.

If you’d like to explore your options, get in touch with Hampstead Orthodontic Practice for a free consultation using our full digital diagnostic setup.

FAQs

How does an orthodontist decide between braces and Invisalign?

The decision comes down to your bite, the type of tooth movement needed, and whether you can wear a removable aligner consistently. Simple to moderate cases often suit Invisalign, while complex movements tend to favour fixed braces.

Are fixed braces more effective than Invisalign?

Neither wins across the board. Clinical evidence suggests fixed braces have an edge for torque and rotation, while clear aligners perform well for extrusion. The best system depends on the specific movements your case needs.

Is Invisalign cheaper than metal braces in London?

Not necessarily. Private fees for both systems depend on case complexity, treatment duration and clinician expertise rather than the appliance itself, so costs are usually comparable for similar cases.

Can Invisalign treat complex cases like severe crowding or a large overbite?

Sometimes, but not always. Complex tooth movements can be harder to achieve predictably with aligners alone, which is why some patients switch to fixed braces partway through to finish treatment.

How long does Invisalign treatment take compared with traditional braces?

Simple cases can take around six to 12 months with either system, while more involved bite correction often takes 12 to 24 months or longer. Your orthodontist can give you a realistic estimate once they’ve assessed your bite.