[Orthodontics founded on "proof" or therapeutic decision making based on the literature]

Faced to an abundant literature and to various clinical situations, practitioners are nowadays invited to implement an evidence based approach. This methodology, initially developed in Canada in the 80's, is getting widely used and is perfectly suited for Orthodontics and particularly for the evaluation of interceptive treatments. It is defined as the conscentious, explicit and judicious use of current best evidence in making decisions about the care of individual patients. This approach, which requires four different steps, will initially be presented. A methodological guide that allows to grade the evidence among different research protocols, will then be introduced. At the top of the hierarchy, randomized clinical trials have shown to be the best tools available to evaluate treatment efficiency. Different research designs are finally put forward to evaluate interceptive treatments.