January 09, 2023

Clear aligner practice in Australia.

This weeks post looks at a large-scale survey of clear aligner use in Australia. Interestingly, some of the findings reflected a cautious use of aligners.

We have posted many times on clear aligners.  While we are gaining more knowledge about this treatment from research. I am still unsure on how much aligner treatment is being done and the complexity of the treatments we provide. This new paper from Australia certainly sheds some light on this area.

A team from Adelaide, Australia, did this study. The AJO-DDO published the paper.

A survey of orthodontic clear aligner practices among orthodontists

Maurice J. Meade and Tony Weir

AJO-DDO Online: DOI:https://doi.org/10.1016/j.ajodo.2022.08.018

This picture is my latest experience of Australian culture.  Can anyone identify what is going on here?  I think Martyn Cobourne may be the first to reply?

What did they ask?

They did the study to;

“Provide information on the Clear Aligner Practices of orthodontists in Australia”.

Their secondary aim was

“To determine why some orthodontists do not provide Clear Aligner Treatment”.

What did they do?

They did a nationwide survey.

Initially, they developed and piloted an electronic survey among orthodontists. They used Survey Monkey software.

The questionnaire had 11 sections. I don’t have enough space to go through these in detail. In short, the questionnaire collected data on demographics, the orthodontist’s use of CAT,  their choices of aligners, digital treatment planning, factors influencing case selection, use of IPR, refinement, and patient-reported issues.

The team circulated the questionnaire to all the members of the Australian Society of Orthodontists. The first approach was sent on May 19, 2022. They then sent reminders on June 24, 2022. The survey was closed on June 20, 2022.

What did they find?
  • The initial target sample was 434, and they received complete responses from 237. This was a response rate of 54.6%.
  • The average number of years in practice was 17.16 (SD=11.6).
  • 93.1% used CAT as a treatment method.
  • CAT comprised 24.17 % (95% CI=21.25-27.05) of their caseload.
  • Most orthodontists did less than 50 CATs per year.
  • The most significant influence on their decision to provide CAT was their perception of patient cooperation.
  • The most popular clear aligner system was Invisalign (60%), followed by Spark (20%). Notably, the ease and quality of the digital planning system greatly influenced their system choice.
  • When they looked at the type of cases the orthodontists treated, they found that virtually all respondents were comfortable treating mild crowding. Almost half sometimes combined CAT with fixed appliances. Most did not use dental monitoring.
  • When they looked at hybrid treatment with fixed appliances, they found 5% of cases required fixed appliances to finish. Interestingly, 56% reported starting with fixed appliances and then changing to CAT.
  • The respondents who did not use CAT  felt that fixed appliances provided better outcomes than CAT.

Their conclusions were

  • Most Australian orthodontists provide Clear Aligner Treatment.
  • Clinical practice varied; importantly, premolar extraction treatment was rarely or never carried out by most respondents.
  • There were significant challenges in achieving torque and correction of rotations in CAT.
What did I think?

This study was well done, well written and easy to read.

Whenever we critically analyse a survey, we must carefully consider the response rate and recall bias. This bias means that the responses represent the practitioners’ estimates of activity rather than actual data.

When I looked at the response rate, I was impressed that this was high. Most surveys of this nature have a rate of about 10%, so their results are good. The authors addressed the recall bias by explaining that the responses were similar to those in other studies. I also feel that this approach was the best the authors could do. This is because if we ask potential respondents to provide actual data on caseload etc., this adds to the research burden. There is then a risk that the response rate will drop.

As a result, I felt that this study was useful. However, I was concerned that the study team did not provide information on the non-responders. Unfortunately, this is a significant omission. This is because the sample may be biased towards those regularly using aligners and overestimate some reported values.

Final comments

The findings were interesting. My overall impression from their data was that aligners are used extensively in Australia. It also appears that the orthodontists are conservative in their case selection. In this respect, they concentrate on mild crowding non-extraction cases. This approach seems sensible if we consider that aligners are tooth-tipping devices. Although, I am not sure that the social media aligner heroes would agree with this statement.

Overall, this paper reported useful information that illustrated the “real world” use of aligners. I thought that it was very useful.

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Have your say!

  1. For sure this is the Austalian Pink Floyd show 🙂
    Did I beat Dr. Cobourne?! 😉
    Always interesting to read your blog… And the comments!

    • Yes, you did. You managed to reply about 1 minute after I finished the posting! Thanks for your nice comments about the blog.

  2. Australian Pink Floyd! Highly recommended!
    Yes Stephane – you beat me to it (I was doing a joint clinic)!!!

  3. hmmm as a distant aside — if most orthodontists do less than 50 CAT cases a year — and yet CAT represented 24% (95% CI was fairly tight) — it suggests that most Orthodontists in Australia start something less than 200 total cases a year. Is that seem to be a reasonable assumption/conclusion?
    On a broader perspective — have always enjoyed your blogs! Appreciate all you do!

    • Good point and thanks for the nice comments. I am not sure about the number of case starts in Australia. perhaps, an Australian orthodontist can let us know. It is 19.00 in the UK so I expect the Aussies to be getting up soon?

    • I saw that also and very unlikely that 200 starts is the case. The average ortho in Australia sees about 170 patients per week (with a wide range) working an ~4.5 day week (Aust Orthod J 2020; 36: 138-145). Based on ~6 weekly intervals this would equate to ~600 starts/year which I would think is much closer to the mark.

  4. That braces were needed to finish only 5% of cases and that 56% reported starting with braces and finishing with aligners may be a great compliment to the discernment and the quality of care provided by our peers in Australia. There is a recent article by Neal Kravitz in the AJO-DO showing 17% of CAT patients finishing with braces.

    I have come to look at situations where the patient starts with CAT and ends with braces as most frequently being some form of failure. Sometimes it is a failure on the patient’s part to cooperate as needed and having to phase to braces as a result. Sometimes it is a failure on our part to anticipate the needed biomechanics or staging, anticipate movements that will take too long with CAT, or recognize movements not expected to occur with CAT, and the patient having to phase to braces as a result.

    IMO, the minimal punishment for this, when it is the result of failure, is increased treatment time. The first delay in treatment comes as a result of the psychological stages that must be gone through between first discovering that CAT is not working out, then accepting that it won’t, and finally having the braces placed. The second delay is a result of braces treatment not typically being complimentary to CAT treatment when the braces are placed after CAT as opposed to before. This is because braces are seldom able to take over exactly where CAT left off. There are still the necessary stages in braces of leveling and aligning, middle stage, and end stage finishing. IMO, to do this properly, takes longer overall, when done in this order.

    On the other hand, starting with braces and ending with CAT usually means that the practitioner has anticipated movements which CAT would take too long to accomplish with CAT or would not be accomplish at all with CAT. Then, once these movements are accomplished with braces, the transition to CAT can theoretically be done with no time lost in treatment and with no to minimal compromises. Biomechanically, CAT would seem to be able to take over after braces, when this is appropriate, without any loss in treatment time. Braces do what they do best and CAT is left to do the rest.

    As a result, I have come to look at the former situation, starting with CAT and finishing with braces, as usually a failure of some type. However, the latter situation of starting with braces and transitioning to CAT when and if appropriate, seems to be a testament to the practitioner’s realization of the limits of a treatment modality and their commitment to quality care, though insisting that braces first do what they are they do better.

    That the incidence of going from CAT to braces was only 5% and that 56% reported starting with braces and then transitioning to CAT really does make it appear as though our peers in Australia have the equation correct, what is best for the patient is the most important part.

    finish with clear aligners seems like it may be a compliment

    When they looked at hybrid treatment with fixed appliances, they found 5% of cases required fixed appliances to finish. Interestingly, 56% reported starting with fixed appliances and then changing to CAT

  5. Thank you for reviewing our article, Kevin. We are proud of the Australian orthodontists for their willingness to respond. I would like to point out that although 93.1% used aligners, we did attempt engagement of the remaining 7%. Section L of the survey asked those who did not provide treatment their reasons for their decision and the data was presented in Table 15. The main reasons were the perception that fixed appliances produced superior treatment outcomes as well as concerns about patient compliance and patient expectations.
    I would further like to add that opportunities were given for free-form comments from all respondents and there was a very large number of those- more than 200. This is an extremely gratifying engagement from the respondents and very valuable. Assessment of these comments did not fit the paper, which was already long, but they made for fascinating reading and add another dimension, which hopefully will be reported upon.

  6. Dear Sir,

    Thank you for another reaffirming article that provides valuable evidence to reinforce good practice (dare I say, sets baseline standards of using CAT for the future).

    Dr Robert Kazmierski’s comments are valuable for anyone trying to venture into Clinical Orthodontic practice, whether they are a specialist or a generalist. A practice limited to only CAT is unlikely to be providing the best for ‘all’ the patients in their care. All the more reason for a Specialist Orthodontist to be involved in planning and key stages’ oversight of ongoing treatment.

    Orthodontic techniques like any surgical skill can be continuously refined to push the boundaries of excellence but it is ‘refinement’ that is the keyword here and not ‘replacement’ of one technique with another.

    Thank you as always.

    Sincere regards,

    Karun Sagar, BDS, MSc
    Orthodontic Assistant

  7. Thank-you Maurice and Tony! I would be interested in a follow-up study with the ADA, (Australian Dental Association) to include GP’s as well. The data will then truly represent aligner use in Australia, rather than the sub-sample from the ASO which includes only specialist orthodontists, and perhaps the more “conservative” ones at that.? As a proud member of the ASO, I would expect a high standard of ethics and patient care amongst my peers, I would hope I could say the same if Tony and Maurice could replicate in the wider profession. More work Tony:) Other factors that may be relevant are the market “age”: Australia was the first market outside of USA and Canada to use CAT (22 years), and the hands-on CAT and didactic exposure that orthodontic residents have had for many years in our university programs.

  8. Really valuable and interesting information Tony and Maurice and Kevin. Thank you.

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