Are TADs cost effective? A new trial
The introduction of temporary anchorage devices has revolutionised orthodontic treatment. But, are they cost effective? This new trial gives us an answer.
Temporary anchorage devices are a great method of reinforcing anchorage. Recent systematic reviews have shown that they are effective and safe. The data in this review was based on the effectiveness of TADs. However, in order to complete the picture on this innovation we need to consider cost-effectiveness. This has been nicely addressed in this new paper.
Niels Ganzer et al
European Journal of Orthodontics, 2018, 1–8 doi:10.1093/ejo/cjy041
A team from Sweden did this study the EJO published it.
In their literature review they described the use of miniscrews for anchorage reinforcement. They also discussed the concept of molar block anchorage. This is when the operator prepares anchorage based on the size of the roots of the teeth. For molar block anchorage they tie the second molar, first molar and second premolar together with ligatures to provide an anchor unit to retract a first premolar.
They set out to answer the following main question;
“Will the use of miniscrews as anchorage reinforcement reduce treatment costs when compared to molar blocks”?
What did they do?
They did a randomised controlled trial with a 1:1 allocation. The PICO was
Participants: 11-19 year old orthodontic patients requiring fixed appliance treatment and extraction of maxillary first or second premolar teeth. They were also moderate to high anchorage cases with at least 75% of the extraction space required for en masse retraction.
Intervention: Temporary anchorage device (miniscrews)
Control: Molar block anchorage preparation.
Outcome: Anchorage loss and cost.
They collected data at the start of treatment at the end of the need for anchorage reinforcement.
They also measured tooth movement from 3D scans.
Finally, they calculated the direct cost of the treatment from the material costs of the appliances and the surgery time and the indirect costs from loss of income and transport costs.
What did they find?
They did not provide much information on the amount of anchorage loss in this paper. Nevertheless, they stated that this manuscript was in preparation. They found that the mean loss of anchorage for the miniscrews patients was 1.5mm and 2.8mm for the molar blocks. This is similar to other studies.
When they looked at the costs. The median cost of the miniscrew treatment €4,680 compared to €3609 for the molar blocks. This was a difference of €829.00 and was statistically significant. Importantly, they attributed this to an increased number of attendance and treatment duration for the mini screw group. This was due to a longer finishing time of 5.1 months. They suggested that this was a result of a longer period of mesial movement of the molars after the canines had been retracted.
Finally, they suggested that in cases requiring moderate need for anchorage reinforcement, the use of miniscrews was not cost-effective. However, miniscrews should be used for cases requiring maximum anchorage.
What did I think?
I thought that this was a well done randomised trial. However, it would have been helpful to interpret this data if the paper that outlined the effects of treatment had been published. This is still awaiting publication. I found another paper on this trail in which the investigators reported pain and discomfort. The Angle Orthodontist published this paper. This revealed that the randomisation and concealment were good.
The findings in the current paper were very clinically relevant. The differences in cost were clinically significant. I thought that it was interesting that they felt these had occurred because of the need for forward space closure in the mini screw group. This may represent “incorrect” use of mechanics with a new technique and I wonder if this would not happen now as we are more experienced in anchorage management with TADs?
As usual with clinical papers, it is up to you to interpret the findings. This interesting new paper does provide us with clinically relevant information to give to our patients. I think that we should look forward to all the papers on this trial being published. This is a good paper to discuss in the comments section of this blog. But can we please avoid an extraction/non extraction breathing, profile and other magical stuff discussion?
Emeritus Professor of Orthodontics, University of Manchester, UK.