Can shining a light on teeth with photobiomodulation make them move faster? A new method of speeding up orthodontic treatment.
Can shining a light on teeth make them move faster? A new method of speeding up orthodontic treatment.
We would all like to make teeth move faster and complete our orthodontic treatment in a shorter time. I have previously posted about several recent developments that aim to reduce treatment times which are being marketed without much evidence. This post is concerned with a recent study about photobiomodulation in which low-level light energy is applied to the alveolar bone with the aim of speeding up orthodontic treatment.
Before we look at the paper, I would like to point out that my blog reached a milestone last month. As regular readers know, all the posts last month were about orthodontic extractions. This must have been interesting to people because the blog was accessed 26,000 times by 12,500 visitors. It looks as though this is becoming surprisingly popular..
This week’s post is on a paper that was spotted by Nick Pandis from Corfu, Greece. Nick has been a great support to me on this blog and has provided me with some statistical information on this post.
Shaughnessy, T., Kantarci, A., Kau, C. H., Skrenes, D., Skrenes, S., & Ma, D. (2016).
BMC Oral Health, 1–9. doi:10.1186/s12903-015-0159-7
This paper was published in the open access journal BMC Oral Health. This is a relatively new Journal but has an established editorial board. It does not publish many orthodontic studies.
I have published several posts on methods of making teeth move faster. I have pointed out that current knowledge shows us that developments in “magic” wires and “special” brackets do not seem to have an effect on the rate of tooth movement. Nevertheless, work on the stimulation of bone remodelling in the individual patient may show some promise and is certainly very interesting. Unfortunately, recent evidence suggests that using vibration does not appear to be effective and injection of substances and surgical injury to bone may not be acceptable to our patients.
An alternative appears to be photobiomodulation (PBM). In this technique the alveolar bone is exposed to low-level light therapy. This activates the cellular mechanism that increase blood flow and this leads to optimal tooth movement. This theory is supported by some animal experiments.
This study is a preliminary study that aims to assess the feasibility and impact of an intra-oral PBM device. The manufacturers of the device supported the study but most of the authors were independent and they declared all conflicts.
They tested the null hypothesis that there will be no difference in the rate of orthodontic anterior alignment between PBM and a control group.
What did they do?
They enrolled 19 participants (11-18 years old) who attended a private practice for treatment in the USA. The patients were treated between September 2011 and September 2013.
This was not a randomised trial. The first 8 patients enrolled in the study were in the control group and the subsequent 11 participants received additional treatment with the PBM device. It is important to note that the patients in the control group started treatment before the PBM patients. There was also a change in the type of bracket used in the practice. This meant that the control group was bonded with 018 slot self-ligating speed brackets. But most of the PBM group were treated with 018 slot conventional ligated brackets.
Study casts were taken at
- T0 before bonding
- T1 when the Little’s index was visually detected to be less than 1mm.
They then calculated the weekly rate of crowding resolution. I am not sure how they did this because they did not state when they saw the patients for review appointments.
They carried out a power calculation They also subjected the data to a wide battery of statistical tests.
What did they find?
There was no difference at the start of treatment between the groups for Little’s index scores. They found significant differences in tooth movement between the groups For the PBM group the average rate of tooth alignment was 1.27 mm/week. For the control group this was 0.44mm/week.
What did I think?
I thought that this was an interesting paper that may lead to further studies which could provide us with clinically important information. But we need to be careful in interpreting this study for the following reasons:
- There was an imbalance between the groups in that the PBM group had 44% mandibular arches and the control had 70%. This may be a considerable confounder because there may be differences in the rate of alignment between arches. However, they did account for this, to a degree, in their analysis.
- The participants were not randomly allocated
- The two groups were treated with different brackets!
- The participants were only followed until initial alignment and we do not know the effect of PBM on treatment time to the end of treatment.
- This was a small-scale pilot study with a small sample size. The literature is full of pilot studies suggesting a treatment effect, but when a larger study was carried out the effect disappeared.
It was good to see that the authors drew attention to these issues in their discussion and suggested further work was certainly necessary. This was unlike the recent Acceledent study that showed “positive” results.
So before we all go out buying PBM and selling it to our patients, all we can conclude at the moment is that this new technique may work. In this respect, this was a useful study. Let’s hope that the manufacturers have not started advertising.
Oh no too late….
I looked at their web-based clinical dossier, this includes animal studies, publications in review and low circulation journals which show “positive” effects of this treatment. This then leads to claims that PBM reduces treatment time.
I take it back…. In the land of no evidence; the Salesman is King.
Emeritus Professor of Orthodontics, University of Manchester, UK.