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

vervolg: Another study on piezocision and speeding up tooth movement.

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.

Days to alignment 102 112 -10
95% CI (83-120) (84-139) (-41-20.9)

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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