AcceleDent again! Vibrational force has no effect on tooth movement: A new trial!
No, this is not Groundhog Day. Since my post last week I’ve become aware of a study that has recently been published in the Journal of Dental Research, which is probably the top scientific journal in dentistry. This study showed that AcceleDent had no effect on tooth movement!
In addition to coming to a different conclusion to the study that I reviewed last week, this study was completely different in its scientific content, methodology, writing, presentation and quality of the journal.
NR Woodhouse et al. London.
Journal of Dental Research, May 2015; vol. 94, 5: pp. 682–689. DOI: 10.1177/0022034515576195
This was carried out by a study team based in London and the south-east of England. They tested the null hypothesis that vibration does not increase the rate of tooth movement. They included participants under 20 years old, with mandibular incisor irregularity, requiring extractions and fixed appliance treatment. The participants were randomly allocated to;
- AcceleDent and fixed appliance
- Sham AcceleDent and fixed appliance
- Fixed appliance only.
Experienced orthodontists treated the patients in a standardised way. The primary outcome was the rate of tooth alignment and the secondary outcome was time to complete alignment. They collected data at the following stages of treatment:
- Start of treatment
- initial alignment, defined as the placement of 018 Ni Ti wire.
- Final alignment; defined by completing gauge spent in 019 x 025 stainless steel wire.
An examiner, who was blinded to the allocation measured alignment from dental casts using Little’s index . The sample size calculations clear, randomisation and concealment was are good. The statistical analysis was appropriate.
What did they find?
They found that the use of AcceleDent, either as an active or a sham, had no effect on the rate of alignment or time to full alignment. The only explanatory variable was the initial irregularity index. The greater the initial crowding the greater time to alignment.
They also express their data in terms of a survival curve and I have reproduced this here. This again shows that AcceleDent did not have an effect on tooth movement.
The discussion was a very good précis of the current knowledge of methods to accelerate tooth movement. They pointed out that the study was high-level evidence. They also pointed out that the inbuilt timers in the AcceleDent devices did not work, but this would not influence the result. Some may say that the study does not take into account the amount of use of the AcceleDent and the device may not have had an effect because the patients did not wear it. However, this was a study carried out in the “real world” of orthodontic practice where out patients do not always co-operate and this adds validity to the results.
What did I think?
I thought that this was a well carried out and reported trial that was published in a very high-quality journal. My only criticism is that they reported on the proximal outcome (alignment) and the most important outcome should be the complete duration of treatment. In this respect, I hope that they continue this study until the end of treatment for the patients.
The authors did not have any conflicts of interest and it is also to AcceleDent’s credit that they provided all the devices for the study.
This study was very different from the one that I discussed last week and came to very different conclusions. I cannot help thinking that this must be due to the poor quality of the previous study. It is also worth pointing out that a recent study has revealed that 97% of head to head trials sponsored by industry give results that favour the sponsor’s drug. The whole issue of the running and reporting of industrial funded trials is covered very well in a great book by Ben Goldacre who is a UK based researcher. Details of this can be found here. This is another link to a recent paper that he has produced. He makes great points and we need to learn from his work.
In summary, I feel that we should accept these findings and conclude that, at present, high-level evidence reveals that AcceleDent does not increase the rate of tooth movement.
I look forward to the results being placed on the AcceleDent website, open discussions with their sales representatives (I look forward to having these at the WFO 2015 meeting), their Key Opinion Leaders and, finally, in Seminars in Orthodontics. My final thought is that I cannot help thinking that this is self ligation all over again, and we all know what happened there?
I am taking some breaks over the summer, so the blogs will not be weekly for the next 6 weeks, but keep reading!
Woodhouse, N., DiBiase, A., Johnson, N., Slipper, C., Grant, J., Alsaleh, M., Donaldson, A., & Cobourne, M. (2015). Supplemental Vibrational Force During Orthodontic Alignment: A Randomized Trial Journal of Dental Research, 94 (5), 682-689 DOI: 10.1177/0022034515576195
Goldacre, B., & Heneghan, C. (2015). How medicine is broken, and how we can fix it BMJ, 350 (jun23 1) DOI: 10.1136/bmj.h3397