Do clear aligners really work for teenagers?
Clear aligner treatment for teenagers is now common. Still, we do not know whether it is as effective as fixed appliances. This is because there remains a dearth of high-quality research on the effectiveness of aligners. As a result, this new study provides us with useful information.
A highly regarded team from the University of Washington did this study. The Angle Orthodontist published the paper.
Comparison of outcomes in adolescents treated with aligners versus fixed appliances.
Dayton S. Oki et al
Angle Orthodontist, DOI: 10.2319/100725-841.1
What did they ask?
They did the study to answer the following question.
“What is the treatment efficacy and efficiency of clear aligners compared to fixed appliances for a population of adolescent patients?”
What did they do?
They conducted a retrospective study using readily available records.
They used records from orthodontic patients aged 18 years or younger who were treated with a non-extraction approach or with one lower incisor extraction. Importantly, all records had to be available and adequate. The team selected these cases from the orthodontic clinic database, which contained records for 286 aligner patients.
They also selected individuals treated consecutively with fixed appliances in the same orthodontic clinic during the same time period as the aligner group, using similar inclusion criteria. They matched on age, gender, pre-treatment arch length, and pre-treatment peer assessment rating score.
The study cases were scored using the peer assessment rating system.
They also reviewed the pre- and post-treatment intra-oral photographs to measure the presence and extent of any new or larger white spot lesions.
They performed a sample size calculation based on the percentage of teeth that developed new white spot lesions. This indicated that they needed to examine the records of 29 patients per group.
Finally, they conducted relevant univariate analyses.
What did they find?
Out of a total sample of 286 aligner patients, 255 did not meet the inclusion criteria, leaving 29 aligner patients in the study. A final sample of 29 fixed-appliance patients who met the inclusion criteria was selected.
Each group consisted of 18 males and 11 females, with a mean age of 13.9 years. All patients had no extraction treatment, except for one fixed appliance patient who had a lower incisor extraction.
There were no marked differences between the groups at the start of treatment.
Importantly, the mean pre-treatment PAR score for the aligner group was 23.4 (8.7) points, whereas for the fixed appliance group, it was 24.1 (9.1). These are mild to moderate malocclusions.
At the end of treatment, the post-treatment PAR score for the aligner group was 5.8 (4.1) points, and for the fixed appliance group, it was 7.1 (3.6) points. This indicates a degree of residual malocclusion.
The total treatment time for the aligner group was 22.8 (6.2) months, and for the fixed appliance group, this was 23.7 (4.0) months. These differences were not statistically significant. Yet, for the number of visits, the aligner group had a mean of 15.7 visits, while for the fixed appliance group, this was 21.3. This difference was statistically significant.
Finally, they looked at new or larger white spot lesions. There were no statistically significant differences between the two groups.
Their final conclusions were
“Adolescent patients with mild to moderate malocclusions had similar post-treatment occlusal outcomes when treated with aligners versus fixed appliances”.
“Although the overall treatment times between the two groups were similar, the aligner patients had significantly fewer scheduled visits.”
What did I think?
This study provided useful information on the overall efficiency and efficacy of clear aligners compared with fixed appliances. Treatment outcomes were similar. Aligners may reduce the appointment burden, emergency visits, and the development of white spot lesions.
However, we do need to be somewhat cautious about this study. This is because it was a small retrospective study involving 58 patients at a single clinic. Importantly, treatment allocation was not random. This matters when we consider that patients selected one type of treatment over another. As a result, this study has selection bias, and we need to bear this in mind when considering the findings. Furthermore, we have no information on the completion rates of the treatment. This is very important when we consider the removable nature of the clear aligners.
We also need to consider that according to the PAR scores, these were mild to moderate malocclusions treated on a non extraction basis.
Finally, this study was supported by Align Technology, and the authors clearly stated this.
Nevertheless, I believe this is a positive step forward in aligner research. It indicates that, for certain cases with mild to moderate malocclusion, aligners could be a practical treatment option. Of course, more research is needed, especially the long-overdue RCTs aligners that may never come to fruition!
Emeritus Professor of Orthodontics, University of Manchester, UK.
I understand from a research point of view the allocation of appliance not being random is a concern. But this study reflects real life clinical practice.
If I only offered aligners to a patient who doesn’t want to wear them, the treatment is not appropriate for them as a person and would fail. There must be a degree of patient choice where appropriate when it comes to appliances. Obviously from a biomechanics point of view some malocclusions are better suited to one appliance or another, but there a large middle ground of cases where the patient can choose what suits them. This choice empowers the patient to be a willing participant in their outcome not just a “subject”.
What was the number of aligners both on upper and lower dentitions used during 22.8 (6.2) months.
Did any revisions needed? Also the IPR need should be clarified because nearly all cases were non-ex.
I think that when comparing fixed appliances vs aligner groups these points should also be discussed in the order to understand the pros and cons of these approaches for the patient’s dental health as well as the environment.
This study provides valuable insight into the comparison between clear aligners and fixed appliances, especially when considering treatment outcomes, appointment frequency, and oral health concerns such as white spot lesions. It is interesting to see that both approaches showed similar effectiveness while aligner treatment required fewer visits in this sample. Research like this helps patients and orthodontic professionals make more informed decisions based on evidence rather than assumptions. For more discussions around health education and community-focused initiatives, resources like PB Outreach can also help promote awareness and knowledge sharing.
Thank you again for your take on this needed research. As a fulltime practitioner, and aligner user from day 1, the “rubber hits the road” aspect to me is the 257 patients who did not meet the inclusion criteria. If I could select the 29 from almost 300 mile to moderate malocclusion patients, that would be great. However, I have to deal with all the problems associated with those who were eliminated from this study. For my clinical, day to day practice, I would like to see the team in Seattle publish at least the top ten factors that resulted in such a high percentage of elimination from being considered for this paper.