Letters From Our Readers

To: Editor, The Angle Orthodontist

Re: Response to: Extraction vs nonextraction orthodontic treatment: a systematic review and meta-analysis. Karim Gamal Elias, Gautham Sivamurthy, David R. Bearn. The Angle Orthodontist. 2024; 94: 83–106.

We thank Professor Benson for taking the time to read our work carefully and we understand his comments related to the lack of high-quality primary evidence in this area as he indeed highlighted in his recent scoping review. However, to be evidence-based orthodontists, we do need to rely on the current best evidence and we feel that, in our quantitative analysis, there were findings that are of use to the evidence-based practitioner in their decision making, particularly in terms of treatment duration and arch dimensions and, as such, are pleased to see it is the current “most read” article on the Angle website.

Professor Benson and colleagues have provided a protocol for investigating the difficult-to-research area of extraction vs nonextraction orthodontic treatment.¹  They proposed a well-structured prospective cohort study. However, even this protocol would lead to findings that would be at risk of bias due to the nonrandomized research design and would, therefore, be reported as such in an interventional systematic review. The bar is set high for interventional studies in systematic reviews and the nature of orthodontics, where, for example, blinding is often not possible, leading to much of our decision-making being based on best available evidence even when this is not strictly of the highest scientific quality.

Professor Benson knows well the challenges in delivering high-quality research in orthodontics, of which the lack of funding for orthodontic research is a significant barrier and we are sure he would join us in wanting to raise awareness of the need for greater funding to enable robustly designed orthodontic trials to be undertaken.