Objective:The aim of this study was to explore the methods, reporting and transparency of clinical trials in orthodontics and compare them to the field of periodontics, as a standard within dentistry.Design/setting:Cross-sectional bibliographic studyMethods:A total of 300 trials published in 2017–2018 and evenly distributed in orthodontics and periodontics were selected, assessed and analysed statistically to explore key aspects of the conduct and reporting of orthodontic clinical trials compared to trials in periodontics.Results:Several aspects are often neglected in orthodontic and periodontic trials and could be improved upon, including use of statistical expertise (22.3% of assessed trials), blinding of outcome assessors (62.3%), prospective trial registration (12.0%), adequate sample size calculation (35.7%), adherence to CONSORT (14.3%) and open data sharing (4.3%). The prevalence of statistically significant findings among orthodontic and periodontic trials was 62.3%, which was significantly associated with several methodological traits like statistician involvement (odds ratio [OR] = 0.5; 95% confidence interval [CI] = 0.3–0.9), blind outcome assessor (OR = 0.5; 95% CI = 0.2–1.0), lack of prospective trial registration (OR = 2.8; 95% CI = 1.3–5.9) and non-adherence to CONSORT (OR = 4.5; 95% CI = 1.3–15.8).Conclusions:Although trials in orthodontics seem to be significantly worse compared to periodontics in aspects like trial registration, adherence to CONSORT and declaration of competing interests or financial support, their methods do seem to have improved considerably in recent years.