Useful concepts for critical appraisal 2. Considering Chance.

There is an increasing volume of research undertaken within orthodontics and with this comes a need to evaluate what is available. This short series aims to help the orthodontist revise basic concepts of critical appraisal and pertinent statistics. Clinical Relevance: Critical appraisal skills are valuable tools that can aid clinical decision-making. In this article, we cover concepts including basic descriptive statistics, significance testing and confidence intervals.