Aligner Chewies: What They Do and How to Use Them Properly

Dr. Adrian Lau, Specialist Orthodontist · July 25, 2026

The short answer: chewies are small soft plastic cylinders you bite on to push your aligner fully down onto your teeth. A tray that is not fully seated is not delivering the force it was designed to deliver — so chewies are not a comfort accessory, they are how the plan actually gets applied. Most patients own chewies. Rather fewer use them in the right place.

I hand chewies to patients every week, and the instruction that comes with them is usually “bite on this for a few minutes.” That is not wrong, but it leaves out the part that decides whether they help: where you bite. This article covers what chewies do, the technique, and the point at which a chewie stops being the answer.

What aligner chewies actually do

Your aligner is manufactured for a tooth position slightly ahead of where your teeth are today. To move them, the plastic has to sit fully down over every tooth. When it does not, you get what orthodontists call an air gap — a visible space between the edge of the aligner and the biting surface of the tooth, usually at the back.

An unseated tray is a real problem, not a cosmetic one. The force is being applied to the wrong part of the tooth, or barely at all. Do that for a couple of weeks and your teeth fall behind the plan, which is the ordinary route to poor tracking and eventually a refinement round that adds months.

Fingers cannot fix this. Your jaw muscles are enormously stronger than your fingertips, and biting spreads pressure evenly across the tray rather than pushing on one point. Chewies are simply soft, resilient cylinders to bite on that will not damage the plastic or your teeth — chewies turn your bite into a seating tool.

There is a second effect worth knowing, and it surprises people: chewies often reduce soreness rather than adding to it. A fully seated tray distributes force the way the plan intended, instead of concentrating it on the two or three high points that happen to be touching. If a new tray feels sharply uncomfortable in one spot, a few minutes with chewies is frequently the fix — see what normal aligner discomfort feels like for where the line sits.

How to use chewies properly

This is the part most people get wrong. The instinct is to bite on the front teeth, because that is where chewies naturally go and where you can see what you are doing. But the front teeth are rarely where the seating problem is. Air gaps show up at the back, on molars and premolars, and around teeth with attachments doing difficult work.

A method that works:

1. Seat the tray by hand first. Press it down firmly with your fingers, front to back, both sides.
2. Find the gap before you reach for the chewies. Look in a mirror at your back teeth. Where is the plastic not touching the biting surface? That segment is your target.
3. Work the chewies around the arch. Place the chewies between your teeth at the back on one side, bite firmly and rhythmically for 20 to 30 seconds, then move the chewies along a few millimetres and repeat. Cover the whole arch, then do the other side.
4. Spend most of your chewies time where the gap was. This is the whole point. Two minutes of chewies on the segment that needs it beats ten minutes on the front teeth that were already seated.
5. Check again. The gap should be smaller or gone. On a brand new tray it may take a day or two of repeated sessions to close fully.

Bite firmly on the chewies but do not clench with maximum force. Steady, rhythmic pressure on the chewies does the work — you are seating plastic, not testing your jaw.

How often and for how long

The honest answer is that protocols vary between clinicians, and yours wins. As a general shape:

• First two or three days of a new tray: this is when it matters most. Several chewies sessions a day, five to ten minutes each, is a reasonable target.
• Rest of the tray: once or twice a day on the chewies is usually plenty, mostly as a habit check.
• Every time you put the aligner back in: ten to twenty seconds on the chewies to seat it after a meal costs nothing and prevents the slow drift where a tray never quite goes back down properly.

That last one is the habit I most wish patients formed. Aligners are removed and replaced several times a day, and a tray reseated carelessly after lunch spends the afternoon not quite doing its job. It also pairs naturally with the moment you are already thinking about — putting them back in — which is where wear time quietly leaks.

When a chewie cannot fix it

Chewies solve a seating problem. They do not solve a tracking problem, and telling the two apart saves people weeks.

If you have used chewies diligently on the same segment for several days and the air gap is still there, stop reaching for the chewies and contact your orthodontist. A persistent gap means your teeth are not where this tray expects them to be — the causes are usually not enough daily wear, switching trays early, or a lost attachment. None of those are fixed by biting harder, and pushing on regardless usually makes the next tray worse.

Two other things chewies will not fix: an aligner that is cracked or warped (it needs replacing), and an edge that is cutting into your gum (that needs a quick polish at the clinic, not more pressure).

Choosing and looking after them

There is not much to buy here, and you may not need to buy any chewies at all — many clinics hand them out. If you are choosing:

• Standard firm chewies are the default and suit most people.
• Soft chewies are worth trying if your teeth are very tender in the first days of a tray, though they seat slightly less aggressively.
• Scented ones are purely a preference. The mint fades within a few uses.

Care is simple: rinse chewies after use, let them air dry rather than sealing them damp in a case, and replace them when they stop springing back into shape — flattened, hardened chewies have stopped distributing pressure and are doing very little. Every few weeks is normal. Chewies are cheap, and a tired pair is a false economy.

One caution on searching for them online: “chewies” is also the common name for paediatric sensory chew tubes, which are a completely different product for a completely different purpose. Search for aligner chewies or orthodontic chewies so you get the right thing.

Frequently asked questions

Do I need chewies? Not everybody is given them, and simple cases often track well without. They matter most when you have attachments, complex rotations, or a history of trays not seating. If your orthodontist gave you a protocol, follow it; if you have an air gap and no chewies, ask.

Can I use something else instead of chewies? People improvise with rolled gauze or a clean cloth, and in a pinch that is better than no chewies at all. Purpose-made chewies are soft enough not to damage the plastic and resilient enough to keep working over many bites, which improvised substitutes generally are not.

Do chewies hurt? They can be uncomfortable on a fresh tray, because you are actively pressing teeth that are already tender. That usually eases within the session. Sharp pain in a single tooth is not caused by chewies and should be mentioned to your orthodontist.

Will chewies make my treatment faster? They will not compress the plan. What they do is stop it from running slower than designed, which in practice is the same thing as finishing on time. Seating and hours are the two variables you control.

How many chewies do I need? One at a time, replaced every few weeks. Some patients keep a second one in a bag or at work so that reseating after lunch is actually convenient rather than something they mean to do later.

This article is general information about clear-aligner treatment, not medical advice. Your chewies routine and tray schedule belong with your own orthodontist.

Dr. Adrian Lau (BDS, MClinDent, MOrth) is a specialist orthodontist, founder of Harbourline Orthodontics in Hong Kong, and co-founder & Clinical Director of AlignDay, a privacy-first aligner tracker for iPhone.