Straight teeth at the speed of light?
Straight teeth at the speed of light?
This guest post is written by Padhraig Fleming who is an experienced orthodontic researcher and clinician based in London (South of England). This is about photobiomodulation making teeth move faster…or not…
As an avid blog reader, I am delighted to contribute to Kevin’s blog. Many recent posts have focused on approaches to hasten orthodontic treatment– the present study considers the use of photobiomodulation and is published in a non-orthodontic journal. It may therefore have passed many of us by.
Investigators have developed a range of approaches in an attempt to reduce orthodontic treatment times. These range from invasive surgery to less aggressive but potentially costly non-surgical adjuncts. High-level research studies assessing the effectiveness of these approaches have predominantly given fairly lukewarm results with most exposing little benefit. Furthermore, repeated procedures may be needed to produce sustained surgical acceleration of tooth movement. This is a prospect that might raise anxiety in many patients and may come at a biological cost. As such, an effective non-surgical means of reducing treatment times has potential merit.
This group from Dubai carried out this study published in ‘Lasers in Medical Science’. According to the authors, photobiomodulation involves delivery of light at wavelengths of 600 to 1200 nm inducing increased ATP production. It is thought that this local delivery leads to a rise in energy levels within adjacent osteoclasts and osteoblasts and they proliferate and differentiate. This results in acceleration of orthodontic tooth movement.
Nahaz AZ et al.
Lasers Med Sci. 2017; 32:129-135. doi: 10.1007/s10103-016-2094-5.
What did they do?
They conducted a two-group parallel randomised controlled trial with a 1:1 allocation as follows:
Participants: Mandibular Little’s irregularity index of ≥2 mm and ≤10 mm
Intervention: Orthodontic treatment with self-ligating brackets with supplemental LED photobiomodulation using an OrthoPulse device (Biolux) for 20 minutes daily
Control: Orthodontic treatment with self-ligating brackets
Outcome: Time taken to reduce Little’s irregularity index to below 1mm
They allocated 20 participants to each group. But they did carry out a sample size calculation. They concealed the allocation by using a sealed envelope system. One operator placed all the appliances with a 0.016” heat-activated NiTi wire, followed by a 0.018” NiTi used in all participants. They reviewed the patients every 2 weeks. They ensured that the data analysts were blind to group allocation.
What did they find?
They found no differences between the groups at the start of treatment in relation to age or irregularity index, although the data was a little sparse. The mean time to align the lower anteriors was 68.3 days (SD 28.7) in the test group but was 87.8 days (SD 24.7) in the control group. This difference was statistically significant (P= 0.043), with the authors alluding to a 22% reduction in alignment time related to the use of photobiomodulation.
What did I think?
This is yet another study assessing the utility of adjuncts in speeding up treatment. I am beginning to wonder whether these adjuncts have preoccupied us as researchers a little more than they should. As a result, maybe we are not focusing on some of the more important arbiters of treatment time and outcome? Surely, for example, extraction decisions and timing may be more influential? We have written a paper on this recently (https://progressinorthodontics.springeropen.com/articles/10.1186/s40510-017-0168-y).
In their discussion the authors neatly place their findings in the context of analogous studies, which found acceleration of the order of 30-34%. They do, however, point out that initial alignment is just one element of orthodontics and that further research focusing on space closure or indeed on overall treatment time might be more instructive.
They included patients who promised to be good and use the devices at least 80% of the time. Unfortunately, we know that many of our patients fall short of this standard, introducing some bias.
I also can’t help thinking that the sample size here is also low, the standard deviations are large and there was attrition in both groups. I therefore wonder whether these impressive between-group differences would be borne out in a larger sample and in other settings.
What can we conclude?
Photobiomodulation has the potential to speed up tooth movement. However, we need to carry out further research to prove the value of this approach. It would be ideal if this could chart the course of treatment as a whole.
I remain to be convinced that the use of photobiomodulation is justified and will await further studies before my patients begin to ‘see the light’.
Emeritus Professor of Orthodontics, University of Manchester, UK.