Why do UK orthodontists recommend the extraction of teeth?

One of the great orthodontic debates is on the need to extract teeth to make space for treating malocclusion. This has ebbed and flowed for many years. This discussion has been chiefly based on clinical experience and the influence of extraction and non-extraction gurus. We are currently in a phase of non-extraction treatment. This new paper examined UK orthodontists’ rationale for recommending extraction or non-extraction treatment. I thought that its findings were significant and very clinically relevant.

The authors noted a lack of evidence to explain factors influencing the extraction decision in their literature review. As a result, they carried out this interesting research project.

What did they ask?

They did the study to answer this question.

“What are the factors affecting extraction choices amongst UK specialist orthodontists”?

What did they do?

They did a qualitative study involving 1:1 participant interviews. The team decided to use qualitative methods because it provides a process for obtaining complex information.

They did the following steps.

• Recruited a sample of 20 orthodontists across the UK using a purposive sampling matrix. This means they used a method to identify a representative sample of orthodontists.
• They developed a guide to ensure that the relevant areas were covered in the interviews. They explored many areas pertinent to the extraction decision in the interviews.
• One trained researcher interviewed the participants remotely using Zoom technology.
• A subgroup of the team met regularly to review the interviews’ results and check for data saturation (this is when the findings in the interviews tend to repeat).
• Finally, they analysed the data using thematic and framework analysis.

What did they find?

They interviewed 20 participants; these included 9 females and 11 males with 1-32 years of experience being registered specialists. The mean was 15.2 years.

When they analysed the data, it was possible to identify 5 main themes concerning the decision to extract teeth as part of a course of orthodontic treatment. These were

• Patient-related factors
• Operator factors
• Setting
• Mechanical approaches
• Self-directed ongoing education.

They provided a great deal of information and many interesting participant quotes in the paper. I will describe what I thought were the most important findings.

Patient-related factors

These included dental health, age dental health, soft tissue features, amount of crowding, degree of overbite, and overjet.

Notably, a deep overbite or mild to moderate crowding promoted non-extraction treatment.

When they needed space, the participants suggested that extractions were more efficient than alternatives, for example, distalisation.

They also tended to extract when they found teeth with a poor prognosis.

They also clearly felt that enablers of non-extraction treatment were retrusive soft tissues and bimaxillary retroclination with competent lips. On the other hand, bimaxillary proclination and incompetent lips prompted extractions.

The participants also suggested that if they saw a patient with a retrusive profile, they followed non-extraction treatment, even if this meant accepting a compromised occlusal outcome.

Operator factors

They clearly felt that there had been a reduction in extractions over the past few years. So, in effect,  the overall philosophy of extractions was changing.

Setting

This concerned whether the patient was treated under the National Health Service (at no direct cost) or privately. This is a complex area to explore. However, the most critical finding was that as patients with severe malocclusions could access NHS treatment; these treatments often required extractions. Whereas patients treated privately tended to have milder malocclusions and were treated non-extraction.

Mechanical approaches

The use of functional appliances was associated with a non-extraction approach.

There was a division of opinion about self-ligation. But, again, this was influenced by the current research literature and the feeling that these were good appliances for expansion.

They also felt that social media promoting non-extraction tended to influence their decisions. However, others felt that cherry-picked cases were not represented. Consequently, this information did not influence more experienced practitioners.

I thought that this was a great quote.

“On social media there are a lot of clinicians posting their cases, and it’s almost like you’re a hero if you’ve done it non-extraction which I think is absolutely ridiculous.”

What did I think?

As usual, I will declare an interest as Padhraig Fleming (a major contributor to this blog) was an author of the paper. However, I have not discussed this paper with him.

I thought that this was an exciting piece of work. It was great to see a team investigate a problem with qualitative methods. This type of research is going to have a significant role to play in future orthodontic research. I am convinced that this approach will provide us with helpful information in the future.

When I looked at their findings, I felt they illustrated the extraction decision was rather complex. While this may be obvious. They also showed that specialists take many factors into account when they make their decisions. Importantly, they looked at the malocclusion and the soft tissues. This is important because it illustrates that orthodontists do not simply follow an extraction or non-extraction policy. It counteracts the accusation that orthodontists always extract or do not, regardless of the patient’s characteristics.

They also showed that they were not always able to use scientific evidence. But, again, this emphasises that in the “real world” of practice, they use research evidence, clinical experience, and patient preferences. This is the ideal way to practice evidence-based dentistry.

Final comments

I have only outlined some of this paper’s main findings and discussion. I feel that it is essential that everyone read this, if possible. Unfortunately, it is behind the AJO paywall. Perhaps it could be made open access?

One last thing, now that you have read this post.  I volunteer at Maggie’s Cancer Support Centre in Manchester and am trying to raise donations to support their incredible work.

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