 This study examined the presence of spin on adverse effects of orthodontic interventions in the abstracts of systematic reviews of orthodontic interventions. The findings suggest that end users should be cautious when interpreting results on adverse effects in the abstracts of these reviews, as there is a possibility of uncertainties due to spin, which can lead to misleading conclusions. This article was authored by Pauline A. J. Steigmans, Nicola Di Girolamo, and Raintay Mercinger Reinders.