What Are Invisible Aligners And How Do They Work?

In recent years, orthodontists have noticed an increase in the number of adult patients treated. This is a global trend that isn’t showing any signs of slowing down. The American Association of Orthodontists report one in three orthodontic patients in the USA are now over the age of 18.The demand is driven by technological advancements in the dental and orthodontic industry. Metal braces may not be everyone’s preferred treatment. Though effective, they can cause patients angst, not least because metal braces aren’t a discreet form of teeth straightening.

Nowadays, there are a variety of invisible solutions like clear aligners and lingual braces that offer discreet alternatives to metal braces that are more appealing to both young and young-at-heart patients. Mild to moderate orthodontics can generally be managed by dentists without a specialist referral.

The popularity and accessibility of clear aligner options have helped create an industry worth over US$ 2 billion- an industry expected to grow to over US$10 billion in less than a decade..

The clear choice for teeth straightening

Invisible/clear aligners have taken the orthodontic world by storm. Their burgeoning popularity amplified when newspapers reported that extremely influential stars – including Khloe Kardashian – were choosing aligners over braces for orthodontic treatment.

Part of what makes them so popular is their technology. Clear aligners are removable orthodontic devices worn discreetly over teeth and, as their name suggests, are made from transparent thermoplastic polyurethane. Unless clear aligners are pointed out by the recipient, most people won’t even notice if somebody is wearing them, which is part of the appeal.

How do clear aligners work?

Where fixed traditional braces use brackets and wires to move teeth into their desired position, invisible aligners use a series of custom-fitted transparent plastic shells – known as trays – worn over the teeth for up to 22 hours per day.

Ultimately, both fixed braces and clear aligners move teeth in the same way – by applying gentle sustained force. The only difference is the style of oral appliance used to make that movement.

To find out how clear aligners move teeth, it’s worth taking the time to understand the science behind tooth movement.

The science of tooth movement

Newton’s Third Law of physics states that every action has an equal and opposite reaction and tooth movement is no exception.

When force is applied to teeth, bone tissue on one side of the tooth (the compression side) is broken down, allowing the tooth to move. At the same time, new bone is created on the other side of the tooth (the tension side) to hold the tooth in place.

(it may be a good idea to insert a diagram or video here explaining the process)

This process of breaking down bone and rebuilding is ongoing throughout the treatment, and the jaw itself takes time to stabilize after the teeth are in their new positions. Hence the need for retainers.

Like fixed braces, custom-fit aligners enable teeth to move gradually and predictably with each aligner (tray) moving teeth sequentially – about 0.10 – 0.33 mm.

An important note

Each aligner is ill-fitting at first, meaning snug or tight, but this is deliberate. It’s because the tray has not been shaped to fit your current teeth position. Instead, it’s shaped to fit your predicted teeth alignment for this stage of your movement. In other words

‘Your teeth grow into your new aligner as they move.’

This is why aligners place pressure on the teeth for a few days when first worn, but any discomfort usually subsides after 3 days. On the whole, however, most patients report it to be a comfortable experience.

What affects how tooth movement works?

• Patient compliance
• Failure to follow the plan
• Loss of aligners

Patient compliance is the most important thing to know when it comes to understanding how clear aligners work^. The invisible aligners need to be worn for the recommended duration each day.

Aligners can – and should, however, be removed for meals, but it is up to the patient to ensure they follow the instructions. Failure to do so can lead to discomfort and delayed results.

Patients should also know that they cannot speed up the process by switching trays too early, but they can delay or negatively impact progress if they fail to change trays as per their treatment plan.

Finally, results rely on the trays being worn in the correct order for the right time. If you lose a tray, you can’t switch to the next one up. Instead, your dentist/orthodontist will need to commission a new custom aligner, which will further delay the process.

Who can have invisible aligners? How effective are they?

Orthodontics Australia describes the ideal clear aligner patient as

“Adults who require minor corrections to problems such as mildly crooked, gappy or protruding teeth.”

They point out that aligners can still treat more complex conditions, but results may be less predictable.

Clear aligners can help with:

Crowded teeth	✓
Overbites	✓
Underbites	✓
Crossbites	✓
Open bites	✓
Slight tooth gaps – diastemas	✓

Clear aligners may not be suitable for:

Larger teeth gapping	x
Complex tooth shaping	x
Molar rotations over 20 degrees	x
Severe tooth misalignment	x

Whether or not invisible aligners suit patients’ lifestyles also needs to be considered because some of the impacts on quality of life may be surprising.

For example, a 26-year-old clear aligner patient told Health.com that she hadn’t realized how much she’d miss her regular manicures during her treatment. It’s not that patients can’t get beauty treatments, more that you use your nails to grip your aligner to wear or remove it.

Patients who are not suitable candidates for invisible braces may still undergo traditional orthodontic treatment like fixed braces.

How do you get invisible aligners? A 4-step process

Patients can choose to explore clear aligner therapy in many ways.

• They can opt to visit their regular dentist,
• Go online and apply for direct to consumer “mail-order” aligners or,
• Visit a clinic or store pertaining to a particular aligner brand.

Either way, the actual process for getting clear aligners remains the same.

The scan/impression

Patients will either visit a dentist/orthodontist or a clinical professional to undergo a 3D scan. Alternatively, they can take an online assessment and receive an impression kit at home from this.

The treatment plan

Patients will have an individual plan created that outlines how many trays they will wear, the duration of treatment, and more. They will also be advised if there are any underlying conditions that need attention before treatment can commence.

Production of aligners

No matter which brands patients use, all clear aligners are individually crafted for their teeth, so there will be a short period, usually several weeks, while their aligners are custom-made.

Commencing treatment plan

Once the clear aligners have been manufactured and delivered, patients can commence treatment as per their treatment plan.

You will be issued with most or all of your trays at the time of starting treatment. This is because trays are switched rapidly.

Patients need to do this themselves. Every step is outlined clearly in their treatment plan, and various support options are available from their chosen dentist or direct-to-consumer company.

How long does clear aligner treatment take?

The short answer is between 4-48 months. However, treatment time varies from patient to patient. Mild cases, such as those wanting purely cosmetic results, can be completed in as little as a few months. Age and lifestyle can play a factor as well. Adult teeth will still move and can achieve great results but will take longer to shift than adolescent teeth.

According to Healthline’s medically reviewed statistics, almost all invisible aligner treatment is completed in less than two years, with some patients able to complete theirs in as little as six months. The average duration is about a year; however, patients may have additional treatment time added onto the end of their estimate to ensure they get the results they want.

Pros and cons of clear aligners

Firstly, the pros

Clear aligners are an excellent way for people to achieve straighter teeth. Some of their key advantages include:

• Being virtually invisible– Clear aligners provide the ideal orthodontic treatment for those who don’t want to wear traditional braces.
• A wide choice of clear aligner brands- There are many brands to choose from, giving patients choice in how they receive their clear aligners and how much they pay.
• Comfort- Clear aligners are more comfortable than wire braces and are removable, making eating, drinking, and cleaning teeth easier.
• Less dental visits– dental visits are limited during treatment- and in some cases – no visits are needed at all, making clear aligners a lifestyle-friendly solution.

The cons

Of course, there are always some disadvantages. Clear aligners may not be the best choice when:

• Dealing with complex issues- invisible aligners are best for mild to moderate orthodontic complaints.
• Patients don’t want to comply with the process- Sticking to the treatment plan is key to success.
• Patients won’t commit to wearing them for 22 hours a day- It does require discipline because it’s easy for patients to get into the habit of not wearing their aligners.
• Patients want to claim insurance or benefits- Not all teeth straightening options are available on all plans; for example, any government subsidies the patient is eligible for usually only apply to traditional wire braces.