Invisalign Not Fitting

Invisalign Not Fitting

Invisalign has literally changed the face of orthodontics in the past decades.

It is a ground-breaking orthodontic appliance that shifts your teeth into the right position without the use of metal braces. The entire system is custom tailored for you and made up of clear (transparent) plastic aligners that fit your teeth snugly and straighten them.

Anyone who’s been in the traditional braces type of treatment can attest to how unpleasant having braces on “forever” is, so the idea of wearing plastic invisible aligners for 22 hours and get them off to eat and clean your teeth sounded like a terrific idea.

And it is.

For whoever is eligible to wear the Invisalign aligners, this is a good option.

Yet, our visitors still ask for time to time: 

My Invisalign trays are not fitting! What to do?

The Invisalign trays are created by using your initial moulds and a 3D computer system to create all the steps till your teeth will be perfectly aligned.

Since there is some time between the moulds and the moment you get your Invisalign it is possible for the trays to be a bit tight. I think this would best describe the feeling you have when putting the first aligner on or when changing with the next set. They are tight.

The entire system relies on the fact your teeth need to move to a desired direction. In order to achieve this, each aligner should push or rotate the tooth and it needs to not be a perfect fit for the current situation, but to force the tooth some more.

After wearing your trays for some time, you’ll notice the current set fits nicely. This is called Invisalign tracking (when the aligners stay “snug” on your teeth). At the end of the 1 or 2 weeks / set you’ll be able to take out the trays very fast. The next set will be a bit tricky to put and after few days its getting easier again. By doing this, each set gets your teeth moving to the desired situation.

Getting back to the question at hand …

How to make Invisalign fit again

It’s normal for the Invisalign aligners to not fit perfectly or appear to not be able to be put on your teeth, when you get a new set on your teeth. Normally your orthodontist is the one to put it in place, so he/shell be able to see if there are any issues. There shouldn’t be anything serious, just the fact its gotta be tight, as I mentioned before.

So, I don’t think you need to worry too much.

The pressure you feel when placing your aligners is normal and is actually vital for the entire orthodontic process to work.

Let’s see if we can still do something when the Invisalign trays are not fitting

1. Use Aligner Seaters or Invisalign “Chewies” to push down your Invisalign tray

These are shaped like a cotton roll (but made of a soft chewable material). You can bite on them, as you put your aligners back (after eating and cleaning your teeth) for few minutes (3-5 minutes). 

As you bite down on them, the aligners will slowly slide down.

I personally just clenched my teeth a little, but, it was 15 years ago. So now, with the technology and so many awesome orthodontic supplies to make our lives easier, let’s try the aligner chewies.

2. Wear Your Invisalign Aligners For 22 at Least Hours Per Day!

Orthodontists usually recommend to wear your sets of aligners at least 20 hours a day, but we’ll go one step forward and recommend to wear them as much as humanly possible.

In order for the orthodontic treatment plan to be effective, your Invisalign trays need to stay for a long time on your teeth. Let’s not forget that metal braces are “stuck” on your teeth for 1-2 years and metal is stronger than plastic.

Take your Invisalign aligners only to eat (don’t dilly-dally, eat and then you can still enjoy the company of your peers with the aligners back on). As soon as you finished eating, clean the aligners and also brush / floss your teeth.

By keeping a perfect oral hygiene you keep the Invisalign clear trays in great shape and your teeth will always look amazing.

3. Consider “Backtracking” to Your Previous Set of Aligners

If your current aligner is clearly not fitting at all and it gives you a hard time, maybe you need to stay at this stage a little longer than just few days. Invisalign aligners are supposed to put pressure on your teeth to move them, but if it looks like your are stuck, your orthodontist can recommend to wear a previous set of aligners.

Another personal tidbit: do wear these aligners as much as possible. Whenever I felt like I was stuck with a set that just didn’t fit, I had to admit not wearing my aligners as much as recommended.

4. Ask your orthodontist for a Treatment Revision

Nothing is perfect in this world, nor is Invisalign.

When wearing braces, your orthodontist can easily change the course of your treatment every few weeks. The Invisalign treatment plan is mapped out at the beginnning, starting from the initial molds and getting to the final perfect teeth alignment.

The problems is that your teeth might not always move as desired. 

And, since the orthodontist cannot tweak the treatment mid-process, if your Invisalign aligners really don’t fit and it’s a literal pain to wear them, you might get a treatment revision.

In this case your orthodontist will get new molds and scans, send the data to the Invisalign manufacturer and get your new sets of aligners.

As soon as you get these, remember to wear them at least 22 hours a day and let your orthodontist know if your invisalign is not fitting from now on.

Invisalign Not Fitting FAQ

What happens if Invisalign doesn’t fit?

Switching to a new set of Invisalign aligners will give the impression that they don’t fit. In this case, use Invisalign Chewies to push them down on the teeth. And wait 2-3 days, until the teeth start shifting again and you’ll feel way more comfortable. Do wear your Invisalign trays 22 hours a day!

Is it normal for aligners to not fit?

Yes. In most cases they actually fit, but since it’s a new set, which is supposed to “move” your teeth even further into the desired position, feeling tight is absolutely normal. For any concerns, discuss with your Orthodontist.

How do I know if my Invisalign isn’t fitting?

Poor tracking means that the Invisalign trays really don’t fit, and it’s not because of a new set you need “break in”. In this case the aligner is loose on your molars (back teeth), they don’t fit a tooth or you can easily notice a gap between the Invisalign tray and your teeth. If the trays align properly with your teeth outline, than Invisalign is tracking properly and it’s most likely an issue of new aligners you are not yet used to.


  1. Maria

    How to know if Invisalign fits? I am straightening my teeth with Invisalign, but, after reading your article, I don’t know if my treatment is really working properly. Is there a way for me to see if my Invisalign trays fit properly?

    • Hello Maria and welcome to

      The first person who can tell you, if your invisalign is working properly, is your orthodontist. But, since you asked here, an easy way to see if your invisalign is tracking (we have an entire article on that: is to look in the mirror at your teeth, with your Invisalign on: do you see any gaps between the Invisalign aligner and your gum line? Do you see any “air pockets” in your Invisalign? Are the aligners snug on all teeth (even the molars)? Chances are your Invisalign fits and you are on your way to a gorgeous smile.

      If you are not sure (or the orthodontist hasn’t specified), do ask at your next appointment. Chances are that, if all goes well, your doctor won’t say “hey, they fit perfectly”. If there’s an issue with your Invisalign not tracking properly, your ortho’ will surely do something about it.

      The way you can make sure all is OK is to stick to your treatment as closely as possible. Wear your Invisalign aligners for at least 22 hours/day and you’ll do well.

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