The level of evidence of published articles on orthodontics in PubMed journals from Iran during 2000-2015

Evidence-based dentistry (EBD), including orthodontics, needs the availability and use of the high-quality studies. The aim of this study was to identify the level of evidence (LOE) of Iranian articles on orthodontics published in PubMed.
All the articles on orthodontics published from 2000 to 2015 in PubMed with Iran affiliations were extracted by typing orthodontics medical subject heading vocabulary in the PubMed search. Then, the study design of each article was determined followed by assigning LOE according to Oxford scale whereby systematic review and randomized clinical trial possess highest-LOE and expert opinion has lowest-LOE. Descriptive statistic indices were applied to summarize the results.
Of all the articles, 34.6% were in-vitro, 24.3% were cross-sectional and 8% were randomized controlled trials (RCT). In terms of LOE, just 5% were level 1, whereas 45.9% were non-evidence. The number of articles with high-LOE increased from 2009 to 2015.
The number of orthodontic articles published in PubMed from Iran has increased in recent years. Nonetheless, there are still deficiencies in high-LOE studies.