Clear aligner use in the mixed dentition: Who does what?
This new paper provides information on using clear aligners for mixed dentition interceptive treatment. This area is controversial, and the results give an interesting insight into this treatment.
The whole subject of interceptive mixed dentition treatment is controversial. While orthodontists often carry out this treatment, we do not know much about its effectiveness. As a result, we know even less about using clear aligners for this treatment. While research is lacking, looking at this new paper that reported a survey of clear aligner use for mixed dentition treatment was helpful. This is an excellent first step because It provides case report-level information and may be considered the first research phase.
A team from Virginia, USA did this research. The AJO-DDO published the paper
Nicholas M. Lynch et al.
AJO-DDO online: https://doi.org/10.1016/j.ajodo.2022.11.018
Their literature review indicated that mixed dentition clear aligner treatment is becoming more popular. Furthermore, the companies and their paid clinical salespeople claim that aligners have advantages over fixed appliances for interceptive treatment. These are fewer appointments, fewer emergency visits, less chair time, and reduced treatment time. If this is the case, they are an orthodontic panacea for treating this age group. This would be reflected in the widespread use of aligners.
What did they ask?
- How often do orthodontists provide clear aligners in the mixed dentition treatment (CAMD)?
- What are the indications for doing CAMD?
- What do orthodontists feel about their patient’s compliance and oral hygiene with CAMD?
What did they do?
They did a cross-sectional survey of orthodontists using a 23-question survey. This was sent to a randomised nationally representative sample of orthodontists (n=800) and a specific sample of high-aligner volume orthodontists (n=200. They identified these practitioners from the AAO online data or Align Technologies Invisalign provider website.
They sent out the first survey and followed up with a repeat mailing after six weeks.
What did they find?
One hundred and eighty-one orthodontists returned their survey. Resulting in a response rate of 18.1% (I will return to this later).
I thought that these were relevant and interesting findings:
- Most of the respondents were solo private practitioners (76%).
- They treated 31% of their patients with clear aligners and 69% with fixed appliances.
- In addition, 21% of their patients had phase I or early treatment in the mixed dentition.
- When they looked at this mixed dentition treatment, the orthodontists used clear aligners for 13% of the patients, and 85% were treated with fixed appliances.
- The respondents were more likely to use fixed appliances than CAMD for all clinical conditions except spacing and diastemas.
- Sagittal correction was among the least commonly selected reasons for CAMD.
- There were no differences between the treatments for compliance or treatment duration. However, they felt that oral hygiene was better with CAMD.
- There was a general tendency to increase CAMD over the next five years.
The study team concluded:
“CAMD use is less than FA for mixed dentition treatment, but this will likely grow.
Most respondents thought CAMD was less useful than FA for growth modification, skeletal expansion and habit cessation.”
What did I think?
This paper is another helpful first step in understanding mixed dentition aligner therapy. This is because this data is derived from practitioners’ experience. Significantly, it condenses their clinical experiences, a significant component of evidence-based care.
The results indicate that orthodontists do not use CAMD for all forms of interceptive treatment. Instead, orthodontists use them for simple problems. This reflects the general feeling about using clear aligners (although some may disagree). Importantly, this study points to treatment that could be investigated in larger-scale clinical studies into interceptive treatment.
When I considered the good points of this study, the sample selection method was suitable, the questions were relevant, the data analysis was appropriate, and the paper was well written. My only concern was the response rate. While some may feel this was low, it is similar to or higher than other survey studies. Nevertheless, I wanted some information on the non-responders, which would indicate possible response bias.
This was a useful piece of research that provided good basic information on clear aligner use in the mixed dentition. Importantly, it gave us more information than the type of presentation done by KOLs on the clear aligner circuit who feel that interceptive treatment “cannot be done with fixed braces”.
Emeritus Professor of Orthodontics, University of Manchester, UK.