Development of a core outcome set for use in routine orthodontic clinical trials

A diverse range of outcomes is used in orthodontic research with a focus on measuring outcomes important to clinicians and little consistency in outcome selection and measurement. We aimed to develop a core outcome set for use in clinical trials of orthodontic treatment not involving cleft or orthognathic patient groups.

A list of outcomes measured in previous orthodontic research was identified through a scoping literature review. Additional outcomes of importance to patients were obtained using qualitative interviews and focus groups with adolescents aged 10-16 years. Rating of outcomes was carried out in a 2-round electronic Delphi process involving health care professionals and patients using a 9-point scale. A face-to-face meeting was subsequently held with stakeholders to discuss the results before refining the core outcome set.

After triangulation, a final list of 34 outcomes grouped under 10 domains was obtained for rating in the e-Delphi surveys. Fifteen outcomes were voted “in” after the second Delphi round involving 274 participants with a further outcome being included after the consensus meeting. These were subsequently refined into a final set of 7 core outcomes, including the impact of self-perceived esthetics, alignment and/or occlusion, skeletal relationship, stability, patient-related adherence, breakages, and adverse effects on teeth or teeth-supporting structures.

A bespoke orthodontic core outcome set encompassing both clinician- and patient-focused outcomes was developed. Incorporating this is the first step into providing a more holistic assessment of the impact of treatment while allowing for meaningful comparisons and synthesis of results from individual trials.


Aliki Tsichlaki
Kevin O'Brien
Philip E. Benson
Zoe Marshman
Ama Johal
Fiorella B. Colonio-Salazar
Nicola L. Harman
Padhraig S. Fleming


Journal: American Journal of Orthodontics and Dentofacial Orthopedics
Pages: -
Year: 2020
DOI: 10.1016/j.ajodo.2020.05.010

Further Study Information

Current Stage: Completed
Funding source(s):

Health Area

Disease Category: Child health, Dentistry & oral health

Disease Name: Orthodontics , Malocclusion

Target Population

Age Range: 10 - 18

Sex: Either

Nature of Intervention: Non-surgical, Procedure

Stakeholders Involved

- Clinical experts
- Consumers (patients)
- Patient/ support group representatives
- Policy makers
- Researchers

Study Type

- COS for clinical trials or clinical research


- Consensus meeting
- Delphi process
- Systematic review
- Focus group(s)
- Interview