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Related Experiment Video

Updated: May 22, 2026

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition

Measuring Maxillary Posterior Tooth Movement: A Model Assessment using Palatal and Dental Superimposition

Published on: February 23, 2024

Why does clustering matter in orthodontic trials?

Jayne E Harrison¹, Girvan Burnside

¹Department of Orthodontics, Liverpool University Dental Hospital, Liverpool, UK. Jayne.Harrison@rlbuht.nhs.uk

European Journal of Orthodontics

|May 26, 2012

Summary

This summary is machine-generated.

Clustering in randomized controlled trials (RCTs) is common in orthodontics but often ignored. Failing to account for clustering in trial design and analysis can impact results, affecting sample size calculations and data interpretation.

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Area of Science:

Clinical Trials
Orthodontics
Biostatistics

Background:

Clustering in randomized controlled trials (RCTs) occurs when participants are grouped or multiple measurements are taken from individuals.
Cluster RCTs are prevalent in clinical orthodontic research.
A significant gap exists as only a quarter of published trials account for clustering effects.

Purpose of the Study:

To highlight the importance of considering clustering in RCTs.
To emphasize the implications of ignoring clustering in orthodontic research.
To inform best practices for trial design and analysis.

Main Methods:

Review of clustering principles in experimental design.
Analysis of current practices in published orthodontic RCTs.
Discussion of statistical implications of clustering.

Main Results:

Clustering is frequently observed in orthodontic RCTs.
A low proportion of published trials adequately address clustering.
Inadequate consideration of clustering affects sample size, consent, and data analysis.

Conclusions:

The effects of clustering must be incorporated into the design and analysis of RCTs.
Properly accounting for clustering is crucial for accurate sample size determination.
Addressing clustering ensures the validity and reliability of orthodontic trial findings.