21 October 2020

4 mins read

Clear Aligners Cannot Correct Severe Teeth Conditions. But What Exactly Does “Severe” Mean?

Not sure if you're a suitable candidate for clear aligners? We cover the teeth conditions that cannot be corrected with invisible braces, so you know for sure.

If you’ve been meaning to straighten your teeth, going with invisible braces can seem like a no-brainer decision.



  • Less painful
  • Subtle
  • Budget-friendly (find out just how affordable they are in our pricing guide)
  • More time-efficient


There’s just one catch though…


Clear aligners are not suited for those with ‘severe teeth issues.


But wait, that’s being rather vague–what constitutes ‘severe’?


How do you know if you are one of the chosen ones? Let’s find out.

Severely rotated teeth

If you have a rotated tooth, it’s likely to be highly visible–especially if it’s one of your incisors, the flat teeth at the front of your mouth.


There are several reasons why your teeth are rotated including:

  • Trauma to the tooth during the developmental years
  • Overcrowding
  • Supernumerary (extra) teeth


If your rotated tooth is severe (i.e. more than 40 degrees), clear aligners will not be suitable.


Invisible braces only excel when there’s a broad surface (tooth contact with the aligner) to apply force to; having severely rotated teeth adversely impacts the fit of the aligners, which then diminishes the force it’s able to exert for the necessary shifts.


As such, research has consistently shown that clear aligners are typically limited in correcting severely rotated teeth.

Large tooth gaps

Clear Aligners Cannot Correct Severe Teeth Conditions. But What Exactly Does “Severe” Mean?


Gap teeth, or teeth spacing, refers to when you have large spaces in between your teeth.


Gap teeth are usually the result of a discrepancy between your jaw and teeth size–either your jaw is too large and your teeth too small, or a combination of the two.


Nonetheless, there are other causes of teeth spacing as well:

  • Losing a tooth
  • Having been born without a tooth


While clear aligners are perfect for closing small gaps in the teeth, the same can’t be said for large tooth spacings. Cases where all tooth gaps, combined, total more than 6 mm per dental arch cannot be closed with invisible braces.


That’s because these large gaps are typically the result of losing a back tooth, missing multiple teeth, or a congenitally missing tooth.


Closing large tooth gaps with clear aligners, without additional orthodontic attention and treatment, can worsen your bite (the way your upper and lower teeth come together) and lead to other severe dental problems!

Severely crowded teeth

When you don’t have enough room (i.e. ‘real estate’) in your jaw for your teeth to fit properly, your teeth can overlap, bunch up, and twist–sometimes getting pushed to the front of back. The common signs of overcrowding include:

  • Front tooth or teeth sitting high and pointed outwards
  • Overlapped front teeth in the lower jaw


Lack of orthodontic care, and even genetics (thanks, Mom and Dad!) can all contribute to overcrowding.


If you have severely crowded teeth–where the amount of space needed to align the teeth properly exceeds 6 mm per dental arch, clear aligners will not cut it.


That’s because, in comparison to conventional metal braces, invisible braces can’t exert the necessary force needed to create complex tooth movements in order to correct severe overcrowding.


Also, in cases of severe overcrowding, teeth extraction may be necessary to create space in your jaw.


Patients having premolar extractions may not be suitable candidates for invisible braces as the aligners cannot always keep the teeth upright during space closure.


In other words, there’s a high level of unpredictability involved during the treatment process.

Severe deep overbites

An overbite refers to the vertical overlap between your upper and lower front teeth when you’re biting down.


Most people have at least a little overbite, which is approximately 30% to 50% of the height of the lower teeth. Anything over that, however, is considered a deep bite.


For severe, deep bites, clear aligners alone won’t be a suitable treatment option.

Skeletal malocclusions

This is a developmental deformity which may vary from minor to major malformations of skeletal origin, such as the size, shape, and relative positions of the upper and lower jaws.


With skeletal malocclusions, clear aligners are not the answer. Instead, depending on the patient’s growth status, treatment options commonly include use of the following:

  • Fixed functional appliances (FFAs) to enhance mandibular growth
  • Headgear to restrict maxillary growth
  • Camouflage by extraction of upper and/or lower premolars
  • Surgical correction of the underlying skeletal discrepancy

Open bites

If your lower and upper front teeth do not touch each other when you close your mouth, you have an open bite. Because an open bite may be caused by inherited skeletal problems, the same treatment options apply with skeletal malocclusions (i.e. not clear aligners).


The gold-standard treatment typically involves the combined approach of orthodontic treatment with fixed appliances and orthognathic surgery.

Other cases where extrusion of teeth is required

Just so everyone is on the same page, extrusion refers to the bringing of more of your teeth above the gum line, making it more visible.


Imaginably, this requires the exertion of force to the tooth that’s in the opposite of its root.


Because of the nature of invisible braces, teeth extrusion is almost impossible without the usage of power ridges and attachments–which might then make your invisible braces, well, less invisible.


Read through the entire article, and didn’t relate to any conditions?


Congratulations: clear aligners will (most likely) be all you need to straighten that smile of yours!

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Zenyum provides the perfect option all while making it affordable!

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Clear Aligners Cannot Correct Severe Teeth Conditions. But What Exactly Does “Severe” Mean?