May 01, 2017

Another study on piezocision and speeding up tooth movement.

Another study on piezocision and speeding up tooth movement.

We would all like to make teeth move faster.  But I am not clear on whether this can be done?  This new study on piezocision provides us with some information.

The journals are publishing an increasing number of research projects on methods of speeding up tooth movement. Most of the trials show that there is no evidence to support the effect of the new interventions.  The European Journal of Orthodontics has just published this new study. This adds to our knowledge.

A team from Connecticut did this trial.

Efficiency of piezotome-corticision assisted orthodontics in alleviating mandibular anterior crowding—a randomized clinical trial

Flavio Uribe et al

EJO on line: advanced access.  DOI: 10.1093/ejo/cjw091

In their introduction they outlined that the evidence to support piezocision is somewhat weak.  Although there has been one study that showed a 43% reduction in treatment time.  I posted about this study last year.

What did they do?

They did this trial to find out if piezotome-corticision reduced the time to obtain alignment of the lower incisors. This was a two arm RCT and the PICO was

Participants: Adult orthodontic patients with mandibular crowding who were treated on a non-extraction basis with self ligating brackets

Intervention:  Piezotome-corticision (0uch!)

Comparator: No intervention (treatment as usual)

Outcome:  Time to alignment. They defined this as a Little’s Irregularity Index of less than 2mm

They did a blocked randomisation to ensure that there were equal numbers in the groups.  When the consented a participant, they selected their own treatment by drawing a sealed envelope, containing the allocation, from a box.

What did they find?

There were no differences between the groups at the start of treatment.  I have put the outcome data for time to alignment in this table.

Conventional bracketsDamon Brackets
Treatment duration (months)14.5 (95% CI 12.7-16.3)12.25 (95% CI 10.55-13.95)
PAR score00
Gingival Index1.51.5

You can see that there was no difference between the two interventions.

They pointed out that the IRB of their institution would only allow them to penetrate 1mm into the bone cortex instead of the recommended depth of 3mm.  I will return to this later because it is important.  However, it may have influenced their results.

What did I think?

This study is similar to  other trials that have been published. In general, they did the study well and reported it very clearly. I do not have any major concerns with their methods and the results are useful. Interestingly, this is yet another study that has investigated this question and has concluded that there is no evidence that piezocision increases the rate of tooth movement.

We, however, need to be a little cautious in dismissing piezocision completely.  This is because the investigators did not follow the patients until the end of their treatment.  This is the important outcome. However, am not sure whether most patients would be willing to have piezocision every time their appliances were adjusted?  As a result, the results of this study add to our knowledge.

The IRB/ethics committee decision

Occasionally, in a paper there is a sentence that is really interesting and relevant.  In this paper this was the decision of the IRB committee. It is important that the IRB was not prepared to let the clinicians carry out deeper cuts into the bone. This was because they were concerned that root injury was likely.

In other words, they felt that the “recommended” treatment carried significant risk.  This is a great example of the fact that operators can expose their patients to risk by carrying out untested new treatments with no external oversight. Yet, when the new technique is subjected to regulatory assessment, the external body finds that it is not safe.  As a result, I wonder if there are safety risks that are potentially being ignored, by those who practice these techniques?


As usual, I will try and summarise the current state of knowledge.

“Piezocision is a new, relatively invasive, technique that is currently not supported by scientific evidence. Furthermore, external review has suggested that there may be risks to the roots of the teeth, when the recommended technique is carried out”.

Good luck with getting consent when you explain this to your patients…

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Have your say!

  1. Very good this study, Doctor. congratulations…..

  2. Kevin I have to agree with your conclusions
    Over invasive – Agreed
    Risk of root damage – Agreed
    It does not speed up tooth movement – Disagree .
    Speaking to operators of this technique it is spectacularly quick.
    Another depressing example of how a scientific study , alters a good clinical technique slightly , and then declares it defunct .
    They didn’t even get the technique right !

    • Thanks for the comment. While I appreciate that this study was prevented from carrying out the exact prescribed technique, the other studies have come to similar conclusions. I am certain that the reports of other operarators who are using this technique are not sufficient evidence to adopt it.

  3. Very true Kevin. Unfortunately there are so many clinicians who are following a trade person or manufacturer’s recommendation for clinical protocol with little to no biologic basis.

  4. Can I ask a dumb question? I’m still not clear on exactly what piezocision is or how it is done. Is a flap lifted? What is the tool? Where can I find this out please?

  5. Only 1 mm of surgery will not reach the bone marrow.
    For races with thick bones, isn’t it about scratch marks?

    Authors “One main difference between the studies was the depth of the piezocision. The IRB of our institution only allowed to penetrate into the bone cortex up to 1 mm instead of 3 mm described in the technique, since they considered that root injury was likely with deeper penetration.

    It may be therefore speculated that a surgical insult that also involves the trabecular bone may be more effective in affecting the bone remodelling processes and thus increase the rate of tooth movement.”

    This is an answer.

  6. Kevin,
    Why do we as orthodontists not view treatment success in terms of stability of the correction over TIME other than to tell our patients- “Where retainers for a lifetime”??
    Meaning if most treated cases relapse ( as measured by whatever index you wish to chose such as reduction in PAR) given enough time, should we not measure success by how long the correction is maintained ?
    If my house needs painted and the painter I choose explains the cosmetic and functional benefits I will receive by having the house repainted for the cost he/she will charge. If the house looks good for 5 years but then needs repainted was this a success? Do I judge differently if it takes 10 years to be re painted? 20 years?, etc.
    The value we give should be measured in terms of value given that is maintained over time. This allows for comparison between doctor’s, specialists and non specialists and leads to better informed consent and informed patients.

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