Let’s talk about Acceledent….
This is the first post in a new series of posts in which I will discuss old and new developments in orthodontics, that some may consider to be controversial. I thought that I should start with Acceledent. For those who are not aware of this new technology, this is an intra oral device that applies vibration for 20 minutes a day to the teeth of patients who are having orthodontic treatment. The aim of Acceledent is to increase the speed of orthodontic treatment and reduce discomfort.
A large amount of information to both patients and dentists is provided on the Acceledent website. The effects of Acceledent are clearly stated on the front page as
“Through the use of gentle mini pulses, called SoftPulse technology, bone remodelling is accelerated, allowing teeth to move up to 50% faster”.
“Faster tooth movement may decrease the duration of your orthodontic treatment and may help make your orthodontics more comfortable”.
I feel that it is interesting that these are rather cautious, for example “up to 50% faster”. This is similar to my Broadband contract with British Telecom that is advertised as “up to 76Mb” but in reality I get about 30Mb!
Acceledent, to their credit, have been very helpful and they have provided a large amount of information on their website. This is in several main sections and I shall start with the case reports on labial orthodontics studies. There are three case reports that are presented by orthodontic “Key Opinion Leaders” .
For each case the pre-treatment estimated treatment time is presented along with photographs of the treatment and the actual treatment time with Acceledent. These are nicely presented case reports, however, as I have previously discussed in other posts, this is not a strong level of evidence. But they are interesting.
There is another section on scientific evidence. In this section they listed 6 papers describing animal studies. These were concerned with the effect of vibrations on both tooth movement and sutural growth. I am no “scientist” but I think that they provided useful information. They also emphasised to me that if I were a dog or mouse and I was fitted with a brace, I was not going to be long on this earth, as I was going to be sacrificed in the name of orthodontics!
The final section was on clinical evidence and I was much more interested in this. So I had a really good look. Importantly, these papers were not from the orthodontic scientific literature but were published in “professional dental magazines”, for example, Aesthetic Dentistry Today. These were a mixture of expert opinion and single case reports. Again a low level of evidence.
They had, however, included a paper on a randomised controlled trial carried out at the University of Texas. So I decided to have a really close look at this.
What did they do?
They aimed to evaluate whether the use of Acceledent increased the rate of tooth movement.
They enrolled 45 patients (age range 12.4-40.6 years old) who required orthodontic treatment and the extraction of first bicuspids. They were randomly allocated to an active Acceledent device or to a sham Acceledent device. Each patient was followed until only 1mm of extraction space remained to be closed.
Each canine tooth was retracted by sliding mechanics along 018 ss wires. It appears that in every case the anchorage was reinforced by a TAD. At each four weekly visit the distance between the distal bracket of the canine and the TAD was measured with a digital caliper.
What did they find?
They presented data for 39 patients, 21 in the Acceledent and 18 in the control groups. They analysed the data using simple univariate statistics and I would have liked to see a multi-variate analysis that could have considered the effect of confounders, such as gender, initial position of the teeth and age. They presented data on alignment from a sub-sample of 14 patients. This number is too low for any meaningful comparison, so I concentrated on the amount of distal tooth movement of the canines.
I have included a table of the relevant data here.
The effect of Acceledent on tooth movement (mm/wk)
In the paper they presented the SE of the means and I have converted this to the standard deviation and then calculated the 95% CI. These figures may not be 100% accurate as I did not have access to their raw data and I just used the information from the website. Nevertheless, this provides an indication of the uncertainty around this data.
This study shows that the canines in the Acceledent group moved distally on average 0.29mm/week (SD=0.13) and those in the sham group moved 0.21 mm/week (SD=0.12). The 95% Confidence Interval for both groups was 0.06. The mean difference was 0.08mm/wk (95% CI -0.006-0.16). As the confidence intervals and standard deviations are rather wide this means that there is a large amount of uncertainty in this data. This is likely to be caused by the small sample size and natural variation in the rate of tooth movement. Importantly, when we look at the difference between the two groups, the use of Acceledent resulted in a greater amount of tooth movement of only 0.08 mm/week when compared to the sham. I am not convinced that this is clinically significant, even though they reported that it was statistically significant. They also concluded that this meant a 38% increase in the rate of space closure, but again the distances were very small.
What did I think?
To be honest, it is my academic opinion that this was not a good piece of research for the following reasons.
- The age range of the patients was very wide within a small sample.
- There was no sample size calculation.
- It was not possible to completely blind the measurement.
- There was no error analysis of the measurement. This is very important for this study, because of the small amounts of tooth movement that were being measured. For example, the error of the method could be greater than the differences between the groups.
- They assumed that the position of the TAD did not change. It could have moved because of the vibration?
- They only measured one point contact and not bodily movement of the teeth.
- There was no mention of the statistical analysis.
I would be very surprised to see this study published in a quality refereed journal.
I have thought about how I would do this study. I would enrol a sample of children with malocclusions and randomly allocate them to “Acceledent” or “no Acceledent” and measure the time that it took to complete their treatment. If we were to measure tooth movement I would measure this from 3D scans. This would be a challenging study to complete but it would provide us with useful information.
We all want to make teeth move faster. I feel that Acceledent is an interesting concept that is grounded in science. I also wonder if Acceledent could make teeth move faster along the wires because the vibrations would jiggle the teeth and reduce bracket binding?
However, at present the evidence that supports its use and promotion is currently not at a high level and it would be great to see some well carried out trials. Nevertheless, it is to Acceledents credit that they are putting forward their claims in a cautious way and using terms such as “may increase the speed of tooth movement”. Their Key opinion leaders case reports are nicely presented in a great degree of detail. Unfortunately, some orthodontists websites are not taking the same cautious approach, do a google search and see what is going on……
As I have said before, it is up to us as clinician scientists to interpret the evidence and decide whether or not to use a new development. Have a look at the evidence in more detail and decide yourselves!