You put in a new aligner and notice a sliver of air above one tooth. Is that a problem? It might be. Orthodontists call it "not tracking." Here's what it means and what to do.
What does "tracking" mean?
Each aligner is shaped for where your teeth should be at that stage. When your teeth keep up, every aligner fits snugly. That's tracking. When a tooth falls behind, the aligner no longer sits fully on it, and the gap tends to grow with each new tray if nothing changes.
How to check your aligner fit
- Look at the biting edges in a mirror with good light. The plastic should touch the tips of your teeth.
- Look for air gaps, visible as a shiny space between plastic and tooth, often at the front teeth or at a tooth being rotated.
- Check attachments. The bumps on your teeth should sit fully in their pockets in the aligner.
- Compare days. A small gap on day one that closes by day three is normal. One that stays or grows isn't.
Common causes
- Not enough wear time. The most common cause. Teeth need consistent pressure to keep up. See how many hours to wear aligners.
- Switching trays early, before teeth have finished moving.
- Aligners not fully seated after you put them in.
- A lost or broken attachment, which reduces grip on that tooth.
- Difficult movements, like large rotations, that are simply slower for some teeth.
What to do
1. Seat the aligner fully
Press it on with your fingertips, then bite gently on an aligner chewie for a few minutes, several times a day, moving along the arch, focusing on the gap.
2. Maximize wear time
Aim for your full daily goal, or a bit more if your provider agrees.
3. Don't move to the next tray yet
If the current tray doesn't fit fully by the end of its planned days, switching makes it worse. Many providers will ask you to wear it a few extra days.
4. Contact your orthodontist
Send a photo if they accept them. They may extend your current tray, have you go back to the previous one, replace a lost attachment, or plan refinements.
What not to do
- Don't force a tray that won't go on, and don't bite hard to snap it into place.
- Don't skip ahead to a tray that "fits better."
- Don't trim or modify aligners yourself.
Track it instead of guessing
TrackMyAligners logs your wear time with one tap, reminds you when aligners are out too long, and tells you when to switch trays. Free on iPhone.
The bottom line
A snug fit means your treatment is on plan. If you see gaps that don't close, focus on wear time and seating, hold your current tray, and let your orthodontist decide the next step. Catching it early is much easier than fixing it later.
Frequently asked questions
How do I know if my aligners are tracking?
Look closely in a mirror. The aligner should hug every tooth with no visible space at the biting edges. A gap of air between the plastic and a tooth, especially one that doesn't close after a few days, suggests it isn't tracking.
Can aligners fix themselves if they're not tracking?
Small gaps early in a tray often close as you keep wearing it, especially with chewies. Gaps that persist or grow need your orthodontist, who may extend the tray, go back a step, or order refinements.
Should I go back to my previous aligner?
Only if your orthodontist tells you to. Going back is a common fix, but they need to decide based on what they see.
What are refinements?
Refinements are extra aligners made from a new scan partway through or near the end of treatment, used to finish movements that didn't go fully to plan. They're common and not a sign of failure.
This guide is general information, not medical advice. Your orthodontist or dentist knows your case, so follow their instructions if they differ from anything here.