There are several new techniques that we can use to attempt to make teeth move faster. This new trial looks at the pretty invasive technique of piezosurgery.
Piezocision is a “minimally” invasive technique to accelerate tooth movement. This involves causing trauma to the alveolar bone during a course of orthodontic treatment. A team from Turkey and Massachusetts, USA did this study. The EJO published their paper.
Nilüfer İrem Tunçer et al
European Journal of Orthodontics, 2017, 586–594
These investigators wanted to study the effect of piezosurgery on the rate of overjet reduction using en masse mechanics with and without piezocision. They also looked at the effect of the intervention on various biomarkers. I will simply concentrate on the rate of tooth movement because I think that this is the most clinically relevant outcome.
What did they do?
They did a single centre parallel allocation 1:1 randomised clinical trial.
The PICO was:
Participants: 30 orthodontic patients aged 14 years old and above requiring upper and lower fixed appliance treatment with the extraction of four premolars
Comparator: Treatment as usual, no piezosurgery
Outcome: En masse retraction rates of premolar space closure. The investigators measured this directly in the mouth using digital calipers at days 15, 30, 60, 90 and 120 after piezosurgery. This measurement was not blinded.
They also analysed cephalograms taken immediately before piezosurgery, after 28 days and at the end of space closure.
They did a clear sample size calculation and used a randomisation based on sealed envelopes. The patients selected the envelopes after they had agreed to take part in the study. The ceph data was blinded but the intra oral measurement of space closure was not.
Some readers may not be familiar with piezosurgery. This involves:
1 Giving a local anaesthetic
2 Making incisions in the buccal mucosa
3 Making bone cuts 3mm deep in the alveolar bone between all the anterior teeth
4 Stitching everything back again
5 Pain control advice, application of ice bags for 24 hours.
Here is a nice video of this on YouTube
To be honest I am not sure if this can be described as minimally invasive?
What did they find?
After they measured the rates of space closure and analysed many variables from the cephalograms, they found no difference between the groups. Importantly, they did not find any evidence that piezocision influenced the rate of tooth movement.
What did I think?
I thought that this trial was an interesting study. Unfortunately, there was a major problem with the blinding of data collection. It was not clear whether the person who measured the premolar spaces was blinded to treatment allocation. If the investigator was aware of the treatment allocation this study is at high risk of bias. I mailed the author about this and she confirmed that this was the case. She also pointed out that if they had taken study casts at all the data collection points this would have added to the experimental burden of the patients.
I have thought about this carefully and when I looked at the overjet reduction and molar movement from the cephalograms there was also no differences. As a result, I felt that we can conclude that there were no cephalometric differences in the effect of the interventions. There was an absence of evidence for the effect of piezosurgery.
In summary, my main thoughts are that there are issues with the methodology, particularly with blinding. However, piezocision does not look much fun for our patients. As a result, I would hope to see clear clinically significant effects for this intervention. This is not the case for this study.
I have also reviewed other studies on piezocision and they have all showed no or minimal effects. I would not even think about doing this. Does anyone?