Invisalign treats most common alignment problems, including crowded teeth, gaps, overbites, underbites, crossbites, and open bites. Where it runs into limits is with severe skeletal issues, meaning problems rooted in jaw position rather than tooth position. For mild to moderate versions of nearly every bite problem, clear aligners are a viable option.
Crowding
Crowded teeth are one of the most common reasons people look into Invisalign, and aligners handle this well in mild and moderate cases. Orthodontists generally classify crowding by how many millimeters of space your teeth are short: mild is 2 to 4 mm, moderate is 4 to 6 mm, and severe is anything beyond 6 mm.
For crowding under 6 mm, Invisalign can create room by gently expanding the arch or by shaving tiny amounts of enamel between teeth (a painless process called interproximal reduction). Once there’s enough space, the aligners guide teeth into position over a series of trays. Beyond 6 mm of crowding, the math gets harder. Research published in The Angle Orthodontist found that in heavily crowded cases, Invisalign couldn’t expand the arch enough to avoid pushing the lower front teeth forward, which increases the risk of relapse after treatment. Cases with more than 6 mm of crowding often require tooth extraction, and while Invisalign can still be part of the plan, traditional braces may offer more control in those situations.
Gaps Between Teeth
Spacing issues are among the most straightforward problems for Invisalign to correct. Small to moderate gaps close predictably because the aligners simply push teeth together, which is a less mechanically demanding movement than rotation or vertical shifts. Gaps caused by missing teeth or by a significant size mismatch between the jaw and the teeth can be trickier, and your orthodontist may recommend a combination approach, closing some of the space with aligners and filling the rest with a bridge or implant.
Overbite
An overbite means your upper front teeth overlap your lower front teeth more than they should when you bite down. A small amount of overlap is normal, but when it becomes excessive, it can wear down your lower teeth and cause jaw discomfort. Invisalign corrects mild to moderate overbites by gradually tipping the front teeth back and, in some cases, using small tooth-colored bumps (called attachments) bonded to the teeth to give the aligners more grip.
Where overbite correction gets difficult is vertical tooth movement. Pushing teeth deeper into the gumline (intrusion) is one of Invisalign’s weakest movements. A systematic review in the Turkish Journal of Orthodontics found that intrusion accuracy for front teeth ranged from roughly 33% to 45%, meaning the teeth often didn’t move as far as the software predicted. In some cases, teeth that were supposed to intrude actually moved in the opposite direction. This doesn’t mean Invisalign can’t improve an overbite, but deep overbites requiring significant vertical correction may need braces or a combination approach.
Underbite
An underbite occurs when your lower front teeth sit in front of your upper front teeth. The critical question is whether the underbite is dental or skeletal. A dental underbite means the teeth themselves are angled incorrectly, even though the jaws are reasonably well-positioned. Invisalign can tip those teeth into better alignment. A skeletal underbite means the lower jaw physically extends too far forward, and no aligner can reposition bone. Moderate to severe skeletal underbites typically require jaw surgery, sometimes combined with aligners afterward to fine-tune the teeth.
Crossbite
In a crossbite, some of your upper teeth sit inside your lower teeth instead of outside them when you close your mouth. This can happen on one side or both, and it can involve front or back teeth. Invisalign handles mild crossbites effectively, especially when only a few teeth need to shift. Severe crossbites, particularly those involving the back teeth on both sides, often reflect a narrow upper jaw. In adults whose jaw growth is complete, expanding a narrow upper palate may require a surgical assist or a palatal expander before aligners can do their part.
Open Bite
An open bite means your upper and lower front teeth don’t touch when you close your mouth, leaving a visible gap even with your jaw fully shut. This is one of the more challenging conditions for any orthodontic system because closing an open bite requires either pushing front teeth down (extrusion) or pushing back teeth up (intrusion), both of which involve vertical movement. Invisalign can improve mild open bites, but the accuracy of vertical movements is lower than for straightforward side-to-side tooth shifting. Your provider will assess whether the degree of open bite falls within a realistic range for aligners alone.
How Invisalign Compares to Braces
A 2025 meta-analysis covering seven randomized controlled trials found that clear aligners actually scored higher than traditional braces in several finishing quality categories, including how well the teeth fit together when biting, the alignment of the bite from side to side, and overall treatment scores. The two approaches performed equally well for straightening alignment, closing contacts between teeth, and positioning tooth roots at proper angles.
The takeaway isn’t that Invisalign is universally better, but that for the conditions it’s designed to treat, it finishes just as well or better than braces. The gap between the two narrows as case complexity increases. Braces still hold an advantage for large vertical corrections, severely rotated teeth (more than about 20 degrees), and cases requiring significant jaw-level changes.
Invisalign for Children
A product called Invisalign First is designed for children ages 6 to 10 who still have a mix of baby teeth and permanent teeth. It addresses early issues like narrow arches, crowding, crossbites, underbites, overbites, and spacing problems caused by habits like thumb-sucking. The goal of this early phase isn’t to produce a perfect final result. It’s to guide jaw growth and create space so that later treatment, if needed, is simpler and shorter.
What Invisalign Cannot Fix
Invisalign has clear boundaries. It cannot reposition the jawbone, so severe skeletal underbites and overbites are out of scope without surgery. Teeth rotated more than 20 degrees are difficult to grip and turn with a plastic tray. Large vertical movements, whether pushing teeth up or pulling them down, remain unreliable with current aligner technology. Impacted teeth (teeth trapped beneath the gumline) need to be surgically exposed and pulled into place with braces. And very large gaps, typically anything over about 6 mm per arch, may exceed what aligners can close on their own.
If you’re unsure where your teeth fall on this spectrum, a consultation with an orthodontist who offers both braces and Invisalign will give you the most honest assessment. Providers who only offer one system have less incentive to steer you toward the other when it’s the better fit.