AcceleDent again…. The Key Opinion Leaders comment on recent research!

AcceleDent again….  The Key Opinion Leaders comment on recent research!

Regular readers of this blog will know that there is no high quality evidence that vibratory force has an effect on tooth movement.  The last edition of the AJO published a letter from some Key Opinion Leaders for AcceleDent. This post is about their response.

I have posted about AcceleDent several times. In these posts I highlighted that well carried out RCTs showed that there is no evidence that AcceleDent increases the speed of tooth movement.  Peter Miles did a recent study and the AJO-DDO published his paper.    Three well known orthodontists then wrote to the editor to raise concerns about his methods. Importantly, two of the authors reported that they had potential conflicts of interest, as they had roles with AcceleDent. The editor of the AJO-DDO published their letter along with Peter’s reply.    Peter Miles easily addressed all their concerns in his response.

In their letter that they wrote:

“When patients used the device nearly every day (average of 26 times per month for about 7 months), modestly increased rates of dental alignment, leveling, and molar distalization were reported”.

They based this quote on two studies done by Dr Jay Bowman, which he published in the Journal of Clinical Orthodontics.  As a result, I thought that I should have a look at them….

The Effect of Vibration on the Rate of Leveling and Alignment

The Effect of Vibration on Molar Distalization

I looked at both papers separately, but I considered the findings together.

What did he ask?

In the first study he asked if AcceleDent could increase the rate of levelling and alignment.  He did a retrospective study to study the effect of AcceleDent on Class II non extraction treatment.  He identified a sample of 117 patients and divided them into:

• 30 who had AcceleDent treatment. He saw them at four weekly intervals
• 37 who did not have AcceleDent. He saw them at four weekly intervals
• 50 treated before he used AcceleDent  (PAD sample). He saw them at  5-7 week intervals. This means that he treated this group using a different treatment protocol.

He collected data at the start of treatment and at the following points:

• End of alignment; Defined as when a 017×025 SS wire could be fitted
• Levelling: Defined as when a 019×025 SS wire could be fitted. I was not sure if this represented the end of levelling.  This is because some clinicians will use this size of wire for levelling.

I think that we need to consider that these are subjective clinical end points and they could give clinical validity to the study.  Importantly, there was no blinding of the operator to the treatment allocation.  This could, arguably, lead to substantial bias.

What did he find?

I only considered the results of the AcceleDent and control samples, because he treated the PAD sample differently.  I have adapted the results table and calculated the 95% confidence intervals.

He stated that he found a clinical difference in alignment, but this was not statistically significant.  I need to point out that this could have occurred by chance and we should not consider this to be a “true difference”.  However, the difference in levelling was statistically and clinically significant. I have included this data in this table.  While this shows a significant difference, the confidence intervals are very wide. This means that the “difference” he detected could be from 8 to 87 days.

Let’s have a look at the other paper.

What did he ask?

He did this study to find out if AccelDent had an effect on the speed of distal molar movement.  This was a retrospective study.  He identified 30 patients who had AcceleDent and 30 who did not (control).

He collected data at the start of treatment and at the end of distal movement. The operator decided when these stages had been reached. Again, he was aware of treatment allocation.  He gathered data from cephalograms and the patient record.

What did he find?

He found no difference between the groups in molar tipping, intrusion or crown distalisation.  The only difference that he found was that the patients in the AcceleDent group had 1.2mm more distal movement of the crown apex than the control. This is over a time period of approx 220 days. I think?

What did I think?

I will consider these reports together.  In my opinion, they have the following issues

• They are retrospective studies.  This means that they are likely to have selection bias.
• There was no sample size calculation.
• The operator knew the treatment allocation.  This is very important because the data collection points were very subjective and could be influenced by “belief” in a new system.  This is the one of the main reasons for trials being blinded.
• The confidence intervals were very wide. This means that there is a lot of uncertainty in the data.
• There was confusion between statistical and clinically significant differences.

In effect, I felt that the studies were interesting comparison of case series. This is a low level of evidence, but is useful as a primer for further research.

If we ignore these issues. I would like to consider the overall findings of the studies. I think that I can conclude that the only effect of AcceleDent was to;

• Move the root apex of the upper molar 1.2mm more distally
• Reduce the time of levelling by 48 days.  However,  this could easily be from 8 to 87 days.

The authors conclusion

I would also like to point out that Jay Bowman acknowledged the level of evidence of his study and he concluded in his paper;

“Considering that the significance of the effects seems to be balanced on a knife edge, future investigations of the time value of money and the money value of time must be factored into any clinical application”.

I agree with this.  I was, therefore,  confused because in their AJO letter they say;

“When patients used the device nearly every day (average of 26 times per month for about 7 months), modestly increased rates of dental alignment, levelling, and molar distalization were reported”.

Interestingly, AcceleDent presented these papers in a  very positive press release that stated;

“It’s a significant contribution to OrthoAccel’s clinical library of 15 peer-reviewed articles, including three randomized controlled trials. These published articles demonstrate how AcceleDent can be successfully integrated into clinical practice with a variety of preferred orthodontic appliances and treatment protocols to improve predictable outcomes and enhance patient satisfaction.”

While we can consider the AcceleDent statement as product advertising and it is up to us to look at the papers and interpret them.  I am not sure why the Key Opinion Leaders interpreted the papers in this very positive way?

Where does this leave us?

I have thought about the statement from the AcceleDent opinion leaders. My current feeling has not changed.  We have no high level evidence that AcceleDent increases the speed of tooth movement.

It is the AAO Congress next week. I am sure that the AcceleDent stand will be full of sales people and Key Opinion Leaders.  Why not ask them about the research?

You may also ask why I keep posting about interventions directed at speeding up tooth movement.  This is simply because many orthodontists may be ignoring the research evidence and promoting  treatments “aimed at making teeth move faster” to their patients.  I am sure that they are not providing these interventions at no cost.  Are we clinician scientists or salespeople?  I would hope that our profession remains as clinician scientists…