A simple summary of the need for Orthodontic Extractions..
Orthodontic Extractions: a simple summary
This is Billy Biley, a cartoon character drawn by my son when he was seven years old. There may be a deeper meaning to this picture, but it now reflects my panic since I opened the Pandora’s box of orthodontic extractions.
In my previous three posts, I outlined research projects that evaluated the effects of orthodontic extractions on soft tissue profiles and obstructive sleep apnoea. These studies have used several research methods, for example, retrospective analysis, evaluation of “big data” and a systematic review. They have all concluded that extractions did not have a “harmful” effect. But what do I really think?
Whenever we take a clinical decision there is always uncertainty and the role of research is to help reduce uncertainty (see this post). It, therefore, follows that the higher the level of evidence the less clinical uncertainty.
Regular readers will be familiar with the pyramid of evidence and when we apply this to the studies that have been carried out, the level of evidence may be considered not to be high. But does this mean we cannot practice evidence based care when we are faced with the decision to extract or not?
If we only looked at the research evidence this would be the case. Fortunately, evidence-based care is not only based on research but is based on a combination of evidence, clinical experience and patient preference.
So how do I decide?
The most important point that I would like to make is that I do not like recommending orthodontic extractions, they are traumatic to patient and my mechanics are more difficult. I take this decision by using the evidence based care process that I described. Firstly, it is clear to me that there is often no need to extract teeth when there is no crowding. Furthermore, if an overjet is increased I will not extract to retract the upper incisors. I will use a functional appliance that would retract the upper and proline the lower incisors (perhaps creating another problem!).
If there is severe crowding, I am more likely to extract, as in my clinical experience this is the only way to make space. You will note that I will not be developing the arches with special brackets, remarkable removable appliances or myofunctional appliances. This is because there is minimal evidence that these are effective. I also know that I cannot move upper molars more than an average of 2 mm distally. As a result, I feel that the only controversial area on the extraction decision is when there is moderate crowding. It is also important to consider that the decision to extract should not be considered in isolation. I cannot help feeling that “over retraction” of the upper incisors is not the result of the decision to extract, but is mostly influenced by the choice of treatment mechanics. I am, therefore, confident that the profile is unlikely to be unduly influenced, for Class I skeletal patients, if I extract and use correct mechanics.
I also know that relapse is unpredictable and I cannot guarantee to my patients that their treatment will not relapse.
Finally, I think that by now I am a competent orthodontist and I can treat extraction or non-extraction equally well.
As a result of this process, the person who has the final say is my patient. I simply present the the points above and let them decide. It is no surprise that most of them do not want orthodontic extractions and so I tend to treat more moderate crowding cases without extractions. From discussions with colleagues this appears to reflect contemporary orthodontic practice
Why the new controversy?
Orthodontists have been debating the need for extractions for many years. From time to time we think we have an answer. But every now and then the flames are fanned and we start arguing again. This seems to be happening at present and I would like to give my personal opinion on the reasons for this.
I cannot help thinking feel that the people who promote “new” orthodontic techniques and philosophies to general practitioners on short courses, with the aim of getting them to use their appliances are responsible. This is because is also not possible to treat extraction treatment mechanics on a 2 day course. As a result, the people promoting the new developments promote a non-extraction philosophy based on the premise of arch development (expansion).
They also paint a picture of orthodontists being old-fashioned, out of touch and protectionist and the non-extraction/extraction wheel keeps turning…….
I also have come across advertising in the UK that suggests a child can have orthodontic treatment, at no cost on the National Health Service, and they will have to have extractions. But if they wanted their arches “developed” with special brackets or removable appliances then this treatment could be provided but only on a private funding basis. So, this is a serious issue.
In the comments section of my last post people pointed out that studies into extraction/non-extraction do not measure the airway or use 3D measurement. I would hope that if these studies are repeated they could be done prospectively and this would give investigators the opportunity to use contemporary techniques, but there is also a danger of looking for something that is not a problem. Furthermore, it is easy to criticise studies that have been done many years ago. Importantly, I am still to see the evidence for the effectiveness of myofunctional therapy, breathing exercise and influence of airway volume. I may have missed it, so if you are reading this and are aware of any work in this area, can you let me have the references and I will continue the discussion.
Finally, I would like to point out that some readers may think that my interpretation is too simple and I expect that there will be some comments on this post. But remember, if you are going to make claims for certain treatments, philosophies and miracles could you provide some proof?
Emeritus Professor of Orthodontics, University of Manchester, UK.