June 29, 2015

Ground Hog day? AcceleDent again! Vibrational force has no effect on tooth movement: A new trial!

AcceleDent again! Vibrational force has no effect on tooth movement:  A new trial!

No, this is not Groundhog Day. Since my post last week I’ve become aware of a study that has recently been published in the Journal of Dental Research, which is probably the top scientific journal in dentistry. This study showed that AcceleDent had no effect on tooth movement!

In addition to coming to a different conclusion to the study that I reviewed last week, this study was completely different in its scientific content, methodology, writing, presentation and quality of the journal.

Supplemental Vibrational Force During Orthodontic Alignment: A Randomized Trial

NR Woodhouse et al. London.

Journal of Dental ResearchMay 2015vol. 945: pp. 682689. DOI: 10.1177/0022034515576195

This was carried out by a study team based in London and the south-east of England. They tested the null hypothesis that vibration does not increase the rate of tooth movement. They included participants under 20 years old, with mandibular incisor irregularity, requiring extractions and fixed appliance treatment. The participants were randomly allocated to;

  • AcceleDent and fixed appliance
  • Sham AcceleDent and fixed appliance
  • Fixed appliance only.


Experienced orthodontists treated the patients in a standardised way.  The primary outcome was the rate of tooth alignment and the secondary outcome was time to complete alignment. They collected data at the following stages of treatment:

  • Start of treatment
  • initial alignment, defined as the placement of 018 Ni Ti wire.
  • Final alignment; defined by completing gauge spent in 019 x 025 stainless steel wire.

An examiner, who was blinded to the allocation measured alignment from dental casts using Little’s index .  The sample size calculations clear, randomisation and concealment was are good. The statistical analysis was appropriate.

What did they find?

They found that the use of AcceleDent, either as an active or a sham, had no effect on the rate of alignment or time to full alignment. The only explanatory variable was the initial irregularity index. The greater the initial crowding the greater time to alignment.

They also express their data in terms of a survival curve and I have reproduced this here. This again shows that AcceleDent did not have an effect on tooth movement.

Screen Shot 2015-06-25 at 16.45.41






The discussion was a very good précis of the current knowledge of methods to accelerate tooth movement. They pointed out that the study was high-level evidence. They also pointed out that the inbuilt timers in the AcceleDent devices did not work, but this would not influence the result.  Some may say that the study does not take into account the amount of use of the AcceleDent and the device may not have had an effect because the patients did not wear it.  However, this was a study carried out in the “real world” of orthodontic practice where out patients do not always co-operate and this adds validity to the results.

 What did I think?

I thought that this was a well carried out and reported trial that was published in a very high-quality journal. My only criticism is that they reported on the proximal outcome (alignment) and the most important outcome should be the complete duration of treatment. In this respect, I hope that they continue this study until the end of treatment for the patients.

The authors did not have any conflicts of interest and it is also to AcceleDent’s credit that they provided all the devices for the study.

This study was very different from the one that I discussed last week and came to very different conclusions. I cannot help thinking that this must be due to the poor quality of the previous study. It is also worth pointing out that a recent study has revealed that 97% of head to head trials sponsored by industry give results that favour the sponsor’s drug.  The whole issue of the running and reporting of industrial funded trials is covered very well in a great book by Ben Goldacre who is a UK based researcher.  Details of this can be found here. This is another link to a recent paper that he has produced.  He makes great points and we need to learn from his work.

Final summary

In summary,  I feel that we should accept these findings and conclude that, at present, high-level evidence reveals that AcceleDent does not increase the rate of tooth movement.

I look forward to the results being placed on the AcceleDent website,  open discussions with their sales representatives (I look forward to having these at the WFO 2015 meeting), their Key Opinion Leaders and, finally, in Seminars in Orthodontics.   My final thought is that I cannot help thinking that this is self ligation all over again, and we all know what happened there?

I am taking some breaks over the summer, so the blogs will not be weekly for the next 6 weeks, but keep reading!

Woodhouse, N., DiBiase, A., Johnson, N., Slipper, C., Grant, J., Alsaleh, M., Donaldson, A., & Cobourne, M. (2015). Supplemental Vibrational Force During Orthodontic Alignment: A Randomized Trial Journal of Dental Research, 94 (5), 682-689 DOI: 10.1177/0022034515576195

Goldacre, B., & Heneghan, C. (2015). How medicine is broken, and how we can fix it BMJ, 350 (jun23 1) DOI: 10.1136/bmj.h3397

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Have your say!

  1. Dear Kevin, a great read as always and a wonderful paper by Martyn and his team. My feelings are as yours with SL brackets; are we condemned to repeat the history we have forgotten (even if it was only a few years ago)?

    I spoke on vibration at the recent AAO meeting in San Francisco and presented the preliminary results of a blinded RCT on AcceleDent I am conducting. Unfortunately I cannot breach copyright and other licenses by divulging the results here but it was recorded and it can be accessed online if you have purchased the AAO lectures from that meeting. We will also have the final data collected in September, analysed in October this year and ready for publication soon after that. Interestingly Tim Wheeler from Univ Florida presented soon after my lecture and mentioned a study using vibration with clear aligners and found no difference in the rate of movement or biological markers of movement although it was only a short term trial. The next few years should see more higher level evidence becoming available for an informed choice by both clinicians and the public.

  2. Deja vu all over again. This reminds me of growing mandibles with Frankle’s. At least they did not try to reproduce the monkey torture studies.

  3. From the two studies(RCTs) on Acceldent, analysed by Kevin O’Brien, one gets an impression that ‘all is not well’ in accepting RCTs as ‘golden base of pyramid of Evidence’. It also implies that ‘evidence’ is being ‘created’ by industry, and published by ‘reputed’ journals(Advertising billing ?) Bottomline is that clinging religiously(fanatically) to ‘Evidence’ may not be wise at times!

    • Thanks, I am not sure that it is necessary to fanatically cling to evidence from RCTs, but it is essential to be able to interpret the studies that are published

    • Dear Dr. Mailankody,

      I beg to disagree. Was it not for this RCT, and we kept basing our clinical judgement on case reports, retrospective studies and other non-controlled study designs, I would bet we would still be doting on AcceleDent.

      RCTs (like all studies) can be planned, conducted and reported badly. This does not mean they are a weak study design. This means that maybe we should think about introducing into our under- and postgraduate curricula basic study planning and evaluation.


  4. The study simply shows that treatment with ONLY 20 min of a vibrational device makes no different. Any orthodontist knows that a removable device needs to be worn for prolonged periods. According to to Proffit (1), a removable appliance needs to be worn for at least 8hrs to have a clinical effect.


    1. Proffit WR, Fields HW. Contemporary Orthodontics. New York: Mosby Inc, 2005.

    • 20 minutes wear is the recommended amount by AcceleDent and you are right, is this amount of wear going to make any difference?

      • Kevin: We have taken a different approach by building in the vibrational signal into a biomimetic device that is worn for up to 16hrs per day. We have been selected to take part in a TV documentary on this called “In America”. It’s hosted by James Earl Jones and will likely by aired thru various channels, such as Discovery Health, CNN etc in the latter part of this year.

  5. Hello Dr Kevin

    Your blog is always interesting to read because of your indepth analysis and interpretation.


  6. Dear Jayaram

    I am not religious about anything except for evidence. Evidence is actually anti-religious, it democratises science and its practitioners . If you have any evidence that emerges from a good experiment or study, then I will bow to you and change the way I do orthodontics. Evidence in biology is responsible for eradicating disease and giving us a better quality of life (we also live longer). Evidence in physics allows us to progress to the point that I can write this to you and you can read it in seconds even though we have never met. I urge you not to abandon evidence as the bedrock of your orthodontics.

  7. As an orthodontic student…….i can say that with this conflicting results…….its creating confusion among budding orthodontics like us……….especially when money and ads are the determinant factors in publishing article recently… reading dr kevin’s blog helps to have better understanding of the subject. thanks dr kevin

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