Effectiveness of Clear Aligner Therapy for Orthodontic Treatment: A Systematic Review
Clear aligner therapy for orthodontic treatment has become more and more popular over the past several years. When it was first introduced there seemed to be quite a bit of skepticism as with many new treatment options. There are still many questions about limitations of clear aligners the lack of efficiency when treating certain malocclusions. A recent systematic review published in September 2019 in Orthodontics Craniofacial Research Journal analyzed the effectiveness of clear aligners.1
The efficacy of clear aligners for various types of tooth movement has been argued since the initial debut of the alternate therapy. Tooth movement is clearly very important to set up final treatment goals as well as to calculate treatment time and cost. One of the many limitations disclosed in this review is the lack of a low risk of bias. Most of the studies included a moderate risk of bias, while one had a high risk of bias.
Vertical, horizontal and transverse movements were evaluated for efficacy. Five of the seven studies included in the review assessed predictability of occluso-gingival movement. These studies indicated extrusion of the maxillary anterior teeth was predictable, while the intrusion movement was limited. Furthermore, two additional studies support this finding, confirming anterior teeth were “more occlusal placed than predicted and mesio-buccal cusp of maxillary molar was significantly intruded where no intrusion was planned”. This led to anterior open bite cases associated with clear aligners. The authors note that these results are based on a very low level of evidence and further studies need to be conducted with a low level of bias.
When evaluating horizontal movement, the authors found rotations to be less predictable with clear aligners. Torque control was limited for central incisors, second premolars, as well as first and second molars. There were statistically significant differences in predicted and achieved rotations with clear aligners.
Only one study, with a high risk of bias, evaluated the transverse movement. This study showed transverse dimension movement was more predictable in the mandibular arch than in the maxillary arch.
The review concludes, “most of the tooth movements may not be predictable enough with clear aligner therapy except for minor horizontal teeth movement (with a moderate level of evidence)”. Additionally, the authors conclude that refinements are likely needed in almost every case to overcome the limited predictability of clear aligner therapy.
Have you or your patients had success with clear aligner therapy? How do you feel about DIY clear aligner therapy? Have you seen success with complicated cases that used only clear aligner therapy? Would you consider clear aligner therapy for you or your family?
1. Robertson L, Kaur H, Fagundes NCF, Romanyk D, Major P, Flores Mir C. Effectiveness of clear aligner therapy for orthodontic treatment: A systematic review [published online ahead of print, 2019 Oct 25]. Orthod Craniofac Res. 2019;10.1111/ocr.12353. doi:10.1111/ocr.12353