Clinical trials in orthodontics I: demographic details of clinical trials published in three orthodontic journals between 1989 and 1998.

AIM

To test the hypothesis that there is insufficient evidence available, from clinical trials, to allow evidence-based decisions to be made on the effectiveness of orthodontic treatment.

OBJECTIVES

To identify reports of orthodontic clinical trials and assess their demographic characteristics.

DESIGN

A retrospective, observational study.

SETTING

The American Journal of Orthodontics and Dentofacial Orthopedics, British Journal of Orthodontics, and European Journal Orthodontics.

DATA SOURCE

Clinical trials published between 1989 and 1998.

METHOD

A hand-search was performed to identify all clinical trials. The journal and year of publication, research method, interventions, and sample size of the trials reported were recorded.

RESULTS

One-hundred-and-fifty-five trial reports were identified of which 56 (36.1%) were published from 1989 to 1993 and 99 (69%) from 1994 to 1998. Ninety-nine (69%) reports were published in the AJO-DO, 18 (11.6%) in the BJO and 38 (24.5%) in the EJO. Eighty-five (54.8%) were reports of randomized controlled trials and 70 (45.2%) of controlled clinical trials. The interventions most frequently assessed were bonding materials (21.9%), growth modification treatments (21.3%), and oral hygiene procedures (9.0%). The median sample size was 32 (IQR 19.5, 50).

CONCLUSION

There is sufficient evidence available from clinical trials to warrant doing systematic reviews of orthodontic clinical trials to aid decision-making.