Aligners: How Should They Fit? Tips to Getting the Right Fit
Clinical content featured by Byte is reviewed and fact-checked by a licensed dentist or orthodontist to help ensure clinical accuracy.
We follow strict sourcing guidelines and each page contains a full list of sources for complete transparency.
Table of Contents
- Causes of Fit Issues
- Tips for Fit
- Frequently Asked Questions
Once you’ve inserted your first pair of aligners, you’ll experience decreasing pressure levels on your teeth until the intended treatment is achieved.
On Day One, aligners snap into position, fitting snugly around your teeth. They’ll feel looser in about three to four days as your teeth adjust and shift into place.
Causes of Fitting Issues
Each person has a unique experience with clear aligner therapy (CAT) systems. If your aligners don’t fit right, the cause can be anything, from the technology and materials used to treatment compliance and appliance care.
Potential triggers of CAT fitting or retention problems include:
- Frequent removal
- Chewing on one side of the mouth
- Aligner damage
- Aligner material
- Attachment material
Besides aligners, some patients need special attachments that bond to their teeth. Aligners fit tightly around these attachments, preventing retention issues.
The bond between these reinforcements and teeth weakens faster with frequent removal and insertion of aligners per day. In a few days, the appliance may get loose way before it’s due for replacement.
Chewing on One Side of the Mouth
Because of an uneven application of force when eating, bonded attachments on one side of the aligners can wear out faster than on the opposite side. This can cause a tighter fit on one side, and a poor one on the other.
You may experience this if you regularly eat with your aligners on and if you tend to eat on one side of your mouth all the time. Most of us don’t know which side of the mouth we chew on. If you are someone who wears aligners, you’ll want to pay attention when you eat if you eat with your aligners on.
Composite resin that bonds to the tooth surface is the most critical part of an aligner attachment. Bonding failure can occur when this material is weak due to a manufacturing defect.
It may not adhere strongly enough to the tooth surface, compromising the stability of your aligners.
Tips to Get Aligners to Fit
Here are some of the tips to ensure your aligners fit the way they’re supposed to:
- Get a custom fit
- Get Aligner Attachments
- Choose a Proper Aligner Forming Technique
- Biting down on aligner chewies
- Eat the Right Foods (or Avoid the Wrong Food)
Get a Custom Fit
To minimize the risk of experiencing fitting issues down the line, get custom-made aligners at the outset.
Advanced CAT technology, especially digital imaging and computer-aided 3D modeling, plays a vital custom-staging role today. It enables orthodontists to design and develop highly personalized, accurate teeth alignment plans.
Your dentist can use CAT software to work out the precise amount of force for the micro-movements each tooth makes. They can also more accurately predict the position of each tooth at every stage of treatment, including a year down the line.
Precision matters. Even a miniscule shift of a tooth impacts how the aligner on it fits.
Get Aligner Attachments
Aligner therapy can work without these additional dental appliances. During the customized-staging phase of treatment, your doctor will decide whether you need them for a proper fit.
However, some patients experience fitting problems after beginning CAT without the attachments. If your aligners become too loose or fall out prematurely, you should contact your dentist right away.
You might need custom-made attachments to improve the fit.
These special reinforcements can help improve the comfort of your aligners. Other applications include controlling the amount of force applied to shift your teeth and expanding the range of tooth movement.
Choose a Proper Aligner Forming Technique
Several CAT systems are on the market. How each system works impacts its tooth-retention ability to some extent. You can discuss these options with your doctor for help selecting the right one for your needs.
Generally, high-pressure methods tend to form better fitting aligner surfaces.
Bite Down on Aligner Chewies
Eat the Right Foods (or Avoid the Wrong Food)
Other remedies include:
- Minimizing aligner removal frequency per day
- Not chewing on one side of your mouth when wearing aligners
Are aligners supposed to fit perfectly?
Chances are your first set of aligners won’t fit perfectly. They’ll be a bit tight on day one, before starting to loosen up in a few days as your teeth shift in a series of small movements. This experience occurs when your customized treatment plan is working – meaning that the aligners have your teeth in the desired position.
Should my aligners feel loose?
Your aligners should feel loose only after your teeth have moved to the proper position at each phase of treatment. They should be a little tight the first time.
However, you should call your dentist if the appliances become too loose to the point of falling out or causing serious discomfort.
Risk Factors of Composite Attachment Loss in Orthodontic Patients During Orthodontic Clear Aligner Therapy: A Prospective Study. (January 2021). BioMed Research International.
Retention of Different Orthodontic Aligners According to Their Thickness and the Presence of Attachments. (January 2018). International Journal of Medical Research & Health Sciences.
Has Invisalign Improved? A Prospective Follow-up Study on the Efficacy of Tooth Movement With Invisalign. (September 2020). American Journal of Orthodontics and Dentofacial Orthopedics.
Clear Aligners in Orthodontic Treatment. (March 2017). Australian Dental Journal.