Effectiveness of Clear Aligner therapy for orthodontic treatment: A systematic review

The field of orthodontics has undergone massive changes pertaining to the demographic of patients. Although it has been reported that 75% of all orthodontic patients are under 18 years of age, the composition of orthodontic consumers has been seeing a drastic change in recent years. Today, more and more adults are receiving treatment for their orthodontic malalignments.

This lot of hyperaware orthodontic patrons are also, unsurprisingly, exhibiting grave concern regarding the aesthetic impact of their treatments. This rising demand for a more aesthetic and comfortable orthodontic experience has led to the introduction of new appliances or strategies to meet these cutting modern-day needs.

Clear aligners have become a saviour on this front – not only providing efficient orthodontic corrections but also enabling comfortable wearability and discrete aesthetics. However, very little research has been done to reveal the true effectiveness of clear aligner therapy for orthodontic treatment. This new study sheds a little more light on this subject.

This study was conducted by a team from Canada and published in the Orthodontics & Craniofacial Research.

Effectiveness of clear aligner therapy for orthodontic treatment: A systematic Review. 

Robertson L(1), Kaur H(1), Fagundes NCF(1), Romanyk D(2), Major P(1), Flores Mir C(1). 

Orthod Craniofac Res. 2020 May;23(2):133-142. doi: 10.1111/ocr.12353. Epub 2019 Nov 13.

What they asked

The authors aimed:

“To analyse through a systematic review the effectiveness of clear aligners by assessing: (a) predictability of clear aligners and (b) treatment outcome comparison of clear aligner therapy with fixed appliance therapy.”

What they did

They conducted an electronic search through orthodontic literature dated between January 2014 and April 2019. The following databases were searched without any limitations on language:

• MEDLINE
• EMBASE
• Web of Science
• LILACS

Three of the six authors independently assessed these articles. They also performed the quality assessments of observational studies and randomized control trials using the ROBINS-I tool and Cochrane risk of bias tool, respectively.

They used the GRADE instrument to assess the certainty level for each identified outcome.

What they found

In the end, they found seven articles that met their eligibility criteria. These included six retrospective cohort trials and one randomized controlled trial. They confirmed that most of the included studies (six out of seven) had a moderate risk of bias. The last one of these articles had a high risk of bias.

What we can conclude

They were able to identify a ‘low to moderate level’ of certainty in regard to specific clear aligner therapy tooth movements’ efficiency.

Clear aligners may produce clinically acceptable outcomes that could be comparable to fixed appliances especially when it comes to the buccolingual inclination of upper and lower incisors in mild to moderate malocclusions. However, these studies did not assess all potential clinical scenarios.

Finally, we can conclude that most of the tooth movements may not be predictable enough to be accomplished with only one set of trays with clear aligners despite the recent advances in technology.