You’ve decided you want your teeth straightened and you’ve landed on clear aligners. Now you’re looking at a list of package names and wondering which one you’d actually be given. Here’s what separates them, what the evidence says aligners do well and where they don’t, and who decides which applies to you.
Table of Contents
What Clear Aligners Are, and What They Treat
Clear aligners are a series of removable trays that move teeth a little at a time. The FDA classifies them as prescription devices, safe to use only under the supervision of a dentist or an orthodontist. That single fact shapes everything below: there is no version of this you choose off a shelf.
The AAO lists the conditions aligners most commonly treat: gapped teeth, cramped or crowded teeth, overbite, underbite, open bite and crossbite. The FDA puts the boundary plainly. Aligners are commonly used for mild to moderate issues, and more severe problems may need a different approach.
The AAO puts the limit in one sentence, worth reading before you get attached to the idea: “Clear aligners are not right for everyone.” Which treatment suits you depends on what your teeth and jaws are actually doing, and that is an exam question rather than a website question.
Wondering whether aligners would work for your teeth? Call our Everett dental office and we’ll tell you what an assessment involves.
The Packages, and the One Thing That Separates Them
Invisalign is a brand, and the maker sells it as a set of packages rather than a single product. What separates them is not a different technology. It’s how many aligners the package includes, which sets a ceiling on how far the teeth can travel.
The clearest published account of the range is Align Technology’s own annual report to the SEC, which lists the packages and the number of stages each includes. In the manufacturer’s own description:
- Express, 7 stages, and Lite, 14. Align describes the short packages as being for less complex cases and for relapse after earlier treatment, with Express aimed at aligning the front teeth.
- Go, 20 stages, and Moderate, 20 to 26. Go is a limited package covering the teeth from second premolar to second premolar.
- Comprehensive, with no stage limit: as many aligners as the case requires, in Align’s own words. Align describes it as treating adults and teenagers across a wide spectrum of mild to severe malocclusion, and its features include compensation for teeth that are still coming through and indicators that show whether the aligners are being worn.
- First, which carries no separate stage count because Align lists it inside the comprehensive group. It’s built for younger children who still have a mix of baby and adult teeth.
Align notes that the number of stages can vary by product and by region, so treat those figures as the shape of the range rather than a promise.
Two things are worth saying about that list. No package carries a treatment time. Nothing published by the manufacturer, the FDA or the AAO attaches a duration to any named package, so no duration can accurately be attached to a package name. And no clinical authority recognizes the product names at all. The FDA, the AAO and the ADA discuss clear aligners as a category. The package names come from the company that sells them, which is fine as a description of what you’d be buying and no use at all as evidence about what works.
How Treatment Works
Treatment starts with records: a digital scan of the teeth, and what the AAO calls an accurate diagnosis, which may include an exam, photos and X-rays. From those, the movement is planned as a sequence, and the trays are made to match each step.
You typically wear each tray for one to two weeks before moving to the next. On wear time the sources differ, so here are both: the FDA says at least 20 hours a day, or as your dentist or orthodontist directs. The AAO says at least 22. The FDA’s note on what happens otherwise: treatment may not progress as intended if aligners aren’t worn as directed.
Most cases also need attachments, which the AAO describes as tooth-colored bumps placed on the teeth during treatment to help move them, and removed once treatment is done. They give the smooth plastic something defined to push against.
Plans are sometimes adjusted partway through, and that isn’t a sign anything went wrong. A 2020 systematic review, rating its own evidence low to moderate certainty, found most tooth movements may not be predictable enough to be achieved with only one set of trays, which is why an extra set is sometimes ordered. The manufacturer sells those extra sets as refinements. Your progress is evaluated and monitored periodically along the way.
Everett, WA
Want to know which option fits your case?
An assessment is how that gets settled, and it starts with looking at your teeth and your bite.
How Long It Takes
The FDA gives one figure for clear aligner treatment as a whole: six to 18 months. Not per package, and not per case. The AAO explains why nobody can narrow it from a distance, since the number of aligners and the time needed vary with the individual’s orthodontic issues and the movements required to correct them.
If you’re searching for the quickest route, the FDA has already answered it: “There really is no ‘faster’ method of straightening teeth.” Orthodontics works by applying slow pressure to the bone around a tooth, and that pressure takes the time it takes.
Where Fixed Braces Still Do Better
Here is the other half of the picture, and it matters if you’re choosing.
A 2015 systematic review found extrusion, pulling a tooth further out of the gum, was the movement aligners controlled least well, at 30% accuracy, followed by rotation. A 2025 review of extraction cases found real gaps between what was planned and what the teeth actually did. A third found aligners might not match braces at producing proper contact between the biting surfaces, at controlling the tilt of the teeth, or at widening the arch. The 2015 and 2025 authors both said their own evidence should be read with caution, and none of these reviews looked at your teeth.
The AAO’s own summary of the difference is that braces are attached for the whole of treatment and can treat a wide range of bite problems, including very bad bites.
So this is not a ranking. It’s a list of the movements worth asking about if your case involves them. And the trays have one plain advantage no study is needed for: they come out, so brushing and flossing carry on normally.
What nobody can tell you from the evidence is which is faster. The sources disagree, so this article won’t claim it in either direction.
What to Know Before You Start
The FDA publishes the risks, and they’re worth reading rather than discovering. Teeth may not move as planned. There can be pain or discomfort, irritation, and adverse events including swelling and laceration. Aligners may not be appropriate for every patient. And the one people are most often surprised by: existing dental work such as crowns, fillings and implants may loosen. If you have a lot of it, that’s worth raising when your teeth are assessed.
On what it feels like, the AAO says to expect an adjustment period of about a week, with mild discomfort common for the first few days.
When treatment ends, a retainer holds the result. The FDA’s wording is that after your last set of aligners your dentist or orthodontist may recommend a retainer to keep your teeth in place and prevent them drifting back.
Who Decides Which Option Applies
An orthodontist, working from an exam rather than a description. Because aligners are prescription devices, the choice isn’t yours to make from a list, and that’s a protection rather than a restriction.
The assessment is where the question gets answered, because it shows how far each tooth has to move and whether the bite has to move with it. The AAO suggests you ask, during that conversation, which options may be appropriate for you and why, and expect an explanation of the advantages of each. That’s a reasonable thing to want, and a reasonable thing to be given.
Invisalign at Icon Dental Center
All orthodontic treatment here is done by Dr. Keyvan Sohrabi, our orthodontist, and that includes clear aligners. We’re an Invisalign provider with an iTero scanner, so the scan that starts a treatment plan is done here. Which package a case needs is settled at the assessment.
On cost, the AAO’s general point is a useful starting place: dental plans with orthodontic coverage usually cover braces and clear aligners equally, though every plan differs and yours is worth checking rather than assuming. CareCredit is available, which spreads the cost over monthly payments. We’re in network with Delta Dental/WDS, Regence, Premera, Aetna and Cigna, and out of network with MetLife, United and Concordia. Call and we’ll go through yours.
Common Questions
Does Invisalign hurt?
Expect an adjustment period of about a week, with mild discomfort common for the first few days, which is the AAO’s description. The FDA is more complete, and lists pain or discomfort, irritation, and adverse events including swelling and laceration among the possible risks. So: usually manageable, not nothing, and worth raising if it goes beyond that.
What is a refinement, and does it mean something went wrong?
No. A refinement is an additional set of aligners ordered after the main sequence. A 2020 systematic review, rating its own evidence low to moderate certainty, found most tooth movements may not be predictable enough to be achieved with a single set of trays, which is why an extra set is sometimes ordered. It is a normal part of how this treatment works rather than a correction.