Evidence based orthodontics is not as straightforward as it seems
Over the last few years my blog has been popular because I publish posts on orthodontic evidence. However, can we really practice evidence based orthodontics?
Recently, I have been in many discussions about the adoption of orthodontic techniques in the absence of evidence. Indeed, we are all aware of the inventors, early adopters, snake oil salesman and other promoters making claims about treatment. This has led me to consider whether we can practice evidence based orthodontics. As a result, I have decided to revisit a post that I did several years ago and see if my opinions have changed.
Should we practice evidence-based orthodontics?
This is a basic point and a good place to start. However, people have pointed to me out that orthodontics is unique because it is an art. Furthermore, any the harms that we may cause are usually minor, for example, decalcification and root resorption. It is, therefore, not necessary for us to practice evidence based care.
I disagree. This is because we need to ensure that our treatment is based on evidence, when it is available. We also need to inform our patients of all the potential risks and benefits of treatment. To this end we should be particularly careful of making statements that are not based on good research evidence. I can think of the following examples, the proposed benefits of non-extraction treatment, methods of speeding up treatment and orthodontics that is provided to reduce sleep disordered breathing in children. It is also important for us to consider that charging patients for these treatments does cause harm to their wallets.
Where do we get the evidence?
It is easy to state that the best source is the scientific literature and we can find an increasing number of published trials and systematic reviews. Nevertheless, the quality of the published papers does vary, even in the refereed literature. As a result, it is essential that we can spend time reading the papers and applying our research knowledge to the findings. Alternatively, we can obtain information from magazines, the internet and even this blog. All provide information of varying quality and perhaps lead to confusion.
When I have looked at recent trials, it is clear that studies are being carried in several important areas, for example, self-ligation, methods of speeding up treatment and temporary anchorage devices. While this is great progress, there is a tendency for investigators to concentrate on treatment mechanics. I have done this in several trials that I have done. We still need to investigate some fundamental questions, for example, to identify the benefits of orthodontic treatment, the effects of orthodontic treatment on the airway and whether we can intercept the development of malocclusion. As a result, there are gaping holes in our knowledge. How do we fill these gaps?
It is not all about evidence!
When I look back over the development of evidence based orthodontics I think that one of the problems was that orthodontists “discovered” trials rather late. Several of us became keen to encourage orthodontics to “catch up”. As a result, I put a great deal of emphasis in my writing and presentations on promoting the value of trials. Looking back, I think that I failed to consider that evidence based care is based around a combination of research evidence, patient opinion and clinical knowledge and expertise.
While this concept is now clear to me. I feel that I should point out that this does not mean that these three components are equal. The proportion of each component that influences a final clinical decision is influenced by their relative strengths. For example, there is no doubt that if good scientific evidence is available it should outweigh clinical experience. In fact, we are not practicing ethically if we do not explain the presence or absence of research findings to our patients, so that they can make informed choices about their treatment.
Information we need for patient consent
For example, if we consider the use of TADS. We now have the evidence to say to our patients.
“I would like to use a TAD because it is effective in maintaining anchorage, is easier for you to manage than headgear and it comes with less risks”.
Conversely, if we are proposing that we provide treatment to treat sleep disordered breathing in children, we should be saying
“I would like to propose a treatment that is based on very limited research but my clinical experience suggests that it will help you.”
Importantly, if we are going to take the second approach, we need to justify why our clinical experience is so important in the absence of research. It is also crucial to inform our patients of studies that do not show any benefits for our proposed treatment. Good examples of this are the studies on self-ligation and methods to speed up treatment.
Where do we get our clinical experience and knowledge?
This now brings us full circle. If this is going to be a crucial part of the decision making process, we need to identify how we gain this information. At the simplest level this is by treating our own patients and discussions with colleagues. But, we need to make sure that we do not only just remember the cases where the treatment “worked”. Our failures are of equal importance. We also need to consider our personal clinical experience and consider whether this is sufficient to base treatment decisions upon.
Other sources are attending conferences, the use of social media and listening to advocates for particular treatments and interventions. Again, we need to be cautious as this information tends to be biased towards the successfully treated case. This is because most speakers show their successes (many times). The other source is the salesman and this is not the best way to obtain information for evidence-based care. Nevertheless, this does influence prescribing!
I hope that I have managed to outline the issues that we face. My general feeling is that we should base our treatments on the evidence. When it is absent, we need to accept that our treatment is based mostly on clinical experience. We need to explain this to our patients. When we do this we are practicing evidence-based orthodontics.
Emeritus Professor of Orthodontics, University of Manchester, UK.