Effectiveness of maxillary arch expansion using clear aligners in adult patients: a systematic review and meta-analysis
Abstract
Introduction
Invisalign, introduced by Align Technology, Inc. in 1997, is a system of clear plastic aligners that provides aesthetic orthodontic treatment plus treatment customisation. Created using impressions or intraoral digital scans, patients wear and sequentially exchange removable, 0.75 mm thick polyurethane appliances. The aligners improve smile appearance, correct dentoalveolar posterior crossbites, increase arch length, relieve crowding, and provide more space for tooth alignment. Dentoalveolar expansion is a preferred alternative to interproximal tooth reduction when treating a patient using the Invisalign clear appliance.
Materials and methods
The present review systematically searched electronic databases for prospective and retrospective studies on dentoalveolar expansion using clear aligner therapy in human subjects. The quality of the studies was assessed using the revised Cochrane risk of bias tool.
Results
A high risk of bias was noted in the systematic evaluation of five human trials comprising 254 healthy individuals. The most frequent cause of bias was found to be patient selection. Patient attrition was caused by age-related issues, inadequate compliance, and the lack of blinded outcome evaluation, underscoring the need for better research protocols.
Conclusion
The present study examined maxillary arch expansion in adult patients who received clear aligner therapy. It was found that the efficiency of expansion at the completion of an aligner treatment sequence may be marginally better than at the completion of an expansion treatment due to the hysteresis (the difference between the predicted and actual results of expansion) of Invisalign appliances, which enhances effectiveness and generates the greatest expansion in the first and second premolar region.
© 2024 Anjali Anil Kalekar, Jyoti Manchanda, Santosh Chavan, Wasundhara A. Bhad, Harish Atram, Priyanka Badu, Priyanka Tarde, published by Australian Society of Orthodontists Inc.
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