Orthodontic info
What are Invisalign chewies, and do I need them?
Chewies are small, chewable seating tools you bite on with your Invisalign aligners in, to press a tray fully onto your teeth, and whether you need them, and how to use them, is for your orthodontist to decide.
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Align, the maker of Invisalign, describes its own seating tools as medical-grade silicone chew tools designed to help seat aligners properly by closing any air gaps between the teeth and the aligners. Align says properly seated aligners “increase the likelihood” that the force systems built into the trays are delivered as accurately as possible. Researchers describe the same job: a 2023 study in Progress in Orthodontics names chewies as a tool “to improve aligner seating”, though its patients did not use them, and a 2021 article in BioMed Research International says seaters can make aligners fit more closely to the tooth surface.
A new tray that is not all the way down
A visible gap between a fresh tray and your teeth can be the kind of air gap Align says its seaters are designed to close. Align's directions are to place a seater between your jaws with the aligners in and chew, moving between front and back teeth or biting down on one area, and the practice's Invisalign timeline guide lists seating each aligner fully among the habits that help avoid delays. The one thing not to do is treat a product's directions as your schedule, since they are written for that product. The next step is to ask your orthodontist whether, when and for how long to use chewies.
Trays that fit over attachments
Attachments are tooth-colored bumps bonded to teeth in some aligner plans, and a 2025 review in the Turkish Journal of Orthodontics notes that rectangular attachments require the aligner to be fully seated over them. Force matters too: a 2021 study in BioMed Research International found that using aligner tray seaters was associated with more attachment loss, a result its authors say contrasts with findings by Huang and colleagues, and they suggest the biting force may focus on a single tooth or attachment. The one thing not to do is assume that harder or longer chewing works better. The next step is to ask whether and how your orthodontist wants chewies used with your attachments, and if one comes off, see what to do when an Invisalign attachment falls off.
A tray that still will not seat
A tray that will not seat even with chewies can mean the tray and your teeth no longer match, which is for your orthodontist to evaluate: the American Association of Orthodontists (AAO) says the orthodontist can evaluate both the fit of the aligners and the progress of the teeth against the plan. The one thing not to do is skip ahead to the next aligner, because the AAO says aligners are worn in a set sequence, and the change schedule belongs to your orthodontist, a point the Invisalign treatment page makes too. The next step is a call to the office. Why a tray stops fitting, and whether wear plays a part, is answered on the page asking whether an orthodontist can tell aligner wear.
Whether chewies belong in your plan
We found no AAO answer on chewies, and none of the studies cited here sets a rule for when or how long to use them; Align's directions cover its own products. Because one study linked the same tool that seats a tray to more attachment loss, the choice sits with the orthodontist who planned your tooth movements. Whether chewies belong in your treatment is a question to ask at your consultation or at your next check-in.
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