3 Orthodontic Issues Aligners Cannot Fix

3 Orthodontic Issues Aligners Cannot Fix
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3 Orthodontic Issues Aligners Cannot FixClinical Content Reviewed by Dr. Jay Khorsandi, DDS
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Table of Contents

  1. Limitations of Aligners
  2. Issues Aligners Cannot Fix
  3. Other Issues
  4. Aligners & Hybrid Treatment
  5. References
Orthodontic clear aligners can correct minor to moderate and even some severe malocclusion issues. However, there are some limitations that may require additional equipment or auxiliary techniques.

The Limitations of Orthodontic Aligners

Many people like the idea of using clear aligners to address their malocclusion issues. They are less visible than traditional braces. They can be removed for meals and important events. They are less painful than braces, and they can often move teeth at a faster pace, resulting in a shorter treatment time frame.

However, clear aligners have some limitations. They are not made to be strong enough to cause significant rotation and repositioning of teeth. Depending on the shape of your teeth, their positions and gaps, and your bridgework (using healthy teeth to support an implanted prosthetic tooth), you may have some orthodontic issues that aligners cannot fix.

3 Orthodontic Issues Aligners Cannot Fix

Aligners are valid choices for people with mild to moderate orthodontic issues, like crooked teeth, small gaps between teeth, standard dimension overbites and underbites, open bites, and crowded teeth.

But there are a few orthodontic issues that aligners cannot fix.1 These include the following:

1. Severe Overbite or Underbite

Severe bite issues are not just aesthetic problems. They cause other quality of life problems, such as joint pain, sleep apnea, and overcrowded teeth.

Some people with severe (or deep) overbites or underbites have difficulty chewing food. Others will experience a gradual loss of tooth structure, and others will struggle with speech and other oral functions. Deep overbites or underbites can also affect facial appearance, which can be psychologically distressing.

While basic forms of overbite and underbite can be rectified through the use of aligners, this kind of deep overbite or underbite will require metal braces to correct.

2. Severe Rotation

If teeth are overcrowded, they can rotate in their sockets. Benign tumors, like odontoma, can also rotate teeth.2 Aligners can usually fix minor rotations, but if a tooth is rotated more than 20 degrees, it is an orthodontic issue that an aligner cannot fix.

Crowding (or lack thereof) is one of the main reasons that a tooth may grow rotated or rotate even after it erupts from your gums. If you suffer from overcrowding, this can make your tooth turn to its narrower side in an attempt to keep growing even as there is insufficient room.

On the other hand, if there is too much room in your mouth (a gap between your teeth that is larger than 6 millimeters would qualify for this), an erupting tooth might still rotate because the bite forces in your mouth will be imbalanced, giving the tooth more freedom to spin than it should. Similarly, if your tongue keeps touching a gap in your teeth, it might make the erupting tooth rotate too much.

3. Intrusion or Extrusion

Occasionally, a patient will require an intrusion or an extrusion. These are both accomplished by procedures that move the affected tooth higher or lower in their mouth as needed.

Treatment for tooth intrusion is performed to correct an anterior deep bite. Sometimes, the treatment is performed to correct a posterior tooth that has overerupted, and there is no opposing tooth to resist it.3

Tooth extrusion is the movement of a tooth out of its socket, giving it an elongated appearance. This can be necessary if a tooth was traumatized, like being hit in the mouth and sits “lower” than the rest of your teeth.

Other Issues for Aligners

If you have cavities or gum disease, your dentist or orthodontist will recommend addressing those issues first before prescribing aligners.

Similarly, if you have short teeth, aligners will not be very helpful. They need a larger surface area to grip onto. If you have had extensive past dental work, this might limit the amount aligners can help.

Overall, aligners offer many advantages to patients who are good candidates. But braces apply much stronger force, which increases their ability to shift teeth and address severe malocclusion issues.

If you have severely crooked teeth, a deep overbite or underbite, and painful crowding in your mouth, your dentist or orthodontist will likely prescribe braces over aligners.

Aligners & Hybrid Treatment

Aligners are very popular and sought out by patients because they are not as unsightly as metal braces, they are designed to address mild to moderate malocclusion issues, and they can be removed when you eat.4

However, aligners are made and prescribed to be part of a holistic orthodontic treatment plan. They should not be thought of as a single “cure” for all orthodontic issues.

For some patients, aligners are part of what is known as “hybrid orthodontic treatment,” where they are used in combination with braces and perhaps even surgical interventions, if necessary. This is applicable in cases where the aligners alone are insufficient to remedy severe or complex malocclusions, but there is value to prescribing aligners in addition to wire braces.

Hybrid therapy may be used for older adolescents and adult patients since their periodontal ligaments are not as malleable as those of younger patients. Here, patients typically wear braces for a short period of time. Once the braces have done most of the heavy lifting, they switch to aligners to finish treatment.

Using hybrid therapy allows for many combinations. Sometimes, only the upper teeth require braces, while aligners are used for the lower teeth or vice versa. In other cases, there will be periods when the patient is prescribed braces, followed by a period when they wear aligners; they may then go back to braces until the malocclusion is fully addressed. The dentist or orthodontist might prescribe other devices, like spacers, expanders, or retainers to assist in the treatment plan.

The point of using aligners in this way is to minimize the length of time you have to be in treatment while still prescribing the most effective intervention for your malocclusion and minimizing how visually disruptive orthodontic interventions can be. It is a difficult balance to strike, but the benefits can be worth the effort.

General References

Orthodontic Treatment With Clear Aligners. (June 2018). American Association of Orthodontists. Date fetched: May 23, 2022. 

Orthodontic Treatment of Malocclusion and Its Impact on Oral Health-Related Quality of Life. (May 2016). The Open Dentistry Journal. Date fetched: May 23, 2022.

Medical References

1 Clinical Limitations of Invisalign. (April 2007). Journal (Canadian Dental Association). Date fetched: May 23, 2022. 

2 Simple Orthodontic Correction of Rotated Malpositioned Teeth Using Sectional Wire and 2x4 Orthodontic Appliances in Mixed-Dentition: A Report of Two Cases. (July 2020). Case Reports in Dentistry. Date fetched: May 23, 2022. 

3 Management of an Intruded Tooth and Adjacent Tooth Showing External Resorption as a Late Complication of Dental Injury: Three-Year Follow-Up. (February 2015). Case Reports in Dentistry. Date fetched: May 23, 2022. 

4 Clear Aligner Hybrid Approach: A Case Report. (March 2020). Journal of the World Federation of Orthodontists. Date fetched: May 23, 2022.

Disclaimer: This article is intended to promote understanding of and knowledge about general oral health topics. It is not intended to serve as dental or other professional health advice and is not intended to be used for diagnosis or treatment of any condition or symptom. You should consult a dentist or other qualified healthcare provider with any questions you may have regarding a medical condition or treatment.