What are we reading now? An update on the papers published in the orthodontic literature (1999-2008)

To assess differences between articles published in the Journal of Orthodontics (JO) and European Journal of Orthodontics (EJO) from 1999 to 2008 and compare longitudinal publication profiles.

Retrospective, observational.

The main study examined articles from the American Journal of Orthodontics and Dentofacial Orthopedics and Angle Orthodontist alongside the JO and EJO. All journals were hand-searched to identify eligible articles. A random sample from these articles was obtained to provide 80% power to detect a 100% increase in the number of randomized controlled trials (RCTs) at the 5% level of significance. Each article was classified according to pre-determined criteria by one author (RG). Variations between journals were assessed using the chi-squared test or odds ratio (OR) and 95% confidence intervals (95% CI).

A random sample of 425 articles was obtained from 4301 eligible articles, of which 113 were from the JO or EJO. About 34·5% of articles were from the JO and 66·5% the EJO. Statistically significant differences were found between the type (P<0·001), subject (P=0·049), method/direction (P=0·038) and controls (P=0·006) of articles published in the two journals. When compared longitudinally the proportion of RCTs published between 1989 and 1993 (2·8%) and 1999-2008 (18·5%) was statistically significant (OR=8·0, 95% CI 2·8, 23·1). Statistically significant differences were seen over time in all aspects investigated.

Statistically significant differences were found in the publication profiles of the two orthodontic journals during the period examined and longitudinally. A piece of clinical research was 8 times more likely to be an RCT during 1999-2008, compared to 1989-1993.