An occasionally irregular blog about orthodontics

No evidence that AcceleDent increases the rate of orthodontic space closure: A new trial

By on January 8, 2018 in Recent posts with 5 Comments
No evidence that AcceleDent increases the rate of orthodontic space closure: A new trial

This new paper provides us with further information on the lack of effect of the AcceleDent device. Perhaps it is time for AcceleDent to change their promotional material?

Most readers of this blog will know that I have challenged the claims made by commercial companies and their Key Opinion Leaders. I feel that this is important because orthodontists/dentists are persuading patients to pay for interventions that may lack an evidence base. One of the new interventions is AcceleDent. This is an intra oral vibrator that is used for 20 minutes a day and is supposed to speed up orthodontic treatment. I have posted about this several times.

Peter Miles, an Australian specialist orthodontist, led the team who did this trial. The AJO-DDO published this paper.

Assessment of the rate of premolar extraction space closure in the maxillary arch with the AcceleDent Aura appliance vs no appliance in adolescents: A single-blind randomized clinical trial

Peter Miles, Elizabeth Fisher, Nikolaos Pandis

AJO Volume 153, Issue 1, Pages 8–14


This is the second of a series of papers on their clinical trial. In their first paper they looked at the effect of AcceleDent on initial alignment. They found that AcceleDent did not have an effect. In this paper they looked for any effect on the rate of extraction space closure. They asked:

“Does AcceleDent increase the rate of maxillary premolar extraction space closure”?

What did they do?

They did a single site RCT with parallel 1:1 treatment allocation.

The PICO was:

Participants: Orthodontic patients less than 16 years old, who were planned to have maxillary premolars extracted for the treatment of Class              II malocclusions. They did not plan lower extractions.

Intervention: AcceleDent Aura used for 20 minutes a day

Comparison: No additional intervention: Treatment as usual

Outcome:      Rate of space closure. They measured this from study casts using digital calipers.

Randomisation, sequence generation and concealment were good. The operator and the person who measured the models were blinded to treatment allocation. They did an appropriate statistical analysis.  They carried out a sample size calculation.

What did they find?

They found that the use of AcceleDent had not effect on the rate of space closure. In their univariate analysis they found a difference of only 0.05mm in rate of space closure. This was not statistically significant. When they did the multivariate analysis and included cofounders, the results did not change.

They looked at compliance with the device and found that only 35% of the patients were good compliers (they used the device more than 75% of the suggested time). They also tested for an effect of compliance on the rate of space closure and there was no difference.

What did I think?

I feel that this was a good well run and reported trial. The findings are relevant to our practice.

One potential criticism is that the patients were not very compliant with the AcceleDent device. However, this is likely to reflect “real world” clinical practice. As a result, the study measures clinical effectiveness and is generalisable to most clinical practice.

As a result,  we can conclude that this is another trial that does not find any evidence that AcceleDent is effective. However, I would like to see a study report on the total treatment duration. Nevertheless, if there is no effect on alignment and space closure, I would be very surprised if the overall conclusions change.


I think that the authors nicely summarised the “AcceleDent story” in their discussion when they wrote;

“It is easy to become excited by the possibility of new appliances and techniques in our desire to deliver more efficient and effective orthodontic treatment for our patients. In the wider medical literature, there is evidence of optimism bias when newly introduced treatments are falsely believed to be superior to the older treatments.

Some jump in with fervor and may be considered the pioneers and become key opinion leaders for the manufacturing company, whereas others are more cautious and wait for feedback and evidence. However, as with many new techniques and appliances, those associated with the company usually have the first access to using the appliance clinically and therefore are likely to produce the first publications, but this also leads to a greater potential for bias.

The results they produce need to be examined carefully as to the quality of the study design and this potential for bias; otherwise, the results could be misleading. The problem with studies of low quality and a high risk of bias is that our degree of certainty in believing their findings is low. Patients should be informed of this so that they can make a fully informed decision about trying a new technique or device. Otherwise, the practitioner potentially creates a liability for a breach of contract”.

This is where we are now. I wonder if the AcceleDent Key Opinion Leaders would like to comment?

Here they are..AcceleDent Key Opinion Leaders.




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There Are 5 Comments

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  1. Arthur Cooper says:

    There is no evidence that any system can move teeth at more than 1 mm per month. However adult teeth move at a much slower rate. Has there been any research into accelerating up to 1mm per month in adults?

  2. Jennifer Guidetti says:

    If the purpose of the trial was to measure compliance, then the results could be viewed as being accurate with regard to the overall findings. With only 35% of the participants complying, how can this study prove or disprove the overall effectiveness of the product? I would like to see a study with 90% or better compliance, and not one from Acceledent-but rather an independent party.

    • Kevin O'Brien says:

      Thanks for the comment. I think that this study measures the effectiveness because it takes the level of compliance into account. What they were testing was the effect of giving an intervention to the patients and then measuring the effect, whether they wore the appliance or not. I hope that this is clear and thanks for the good comments.

  3. I agree with Jennifer – if you’re not following the dose prescribed (whether it’s penicillin or accelodent) – it’s not gonna work. My main concern is that 20 mins per day is inadequate. The orthodontic literature shows that a device needs to be in the mouth for about 8hrs to start having a clinical effect.

    • Hi Jennifer and Prof. Singh. Firstly, thank you to Kevin for posting our trial and sharing the result. To clarify and as Kevin has already stated, the main outcome measured was the rate of space closure but we also recorded compliance. The company advocates 20 mins use daily so that is what was prescribed. If ‘success’ is defined as ‘use of the appliance’ then it was only ~35% successful in a real-world scenario (we chose ≥75% use as a good complier). Now if success is faster space closure (as we were assessing), even when we accounted for compliance, there was still no difference in the rate of closure. In other words, the good compliers did not close any faster. For example in Table IV, the best complier (97%) moved at 1.5-1.8mm/mth while a patient using it 23% of the time moved at 1.9-2.1mm/mth. If you wish to know more and do not have access to the full article then it can be viewed at the link below until Feb 14.

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