This paper is an attempt to individuate some principles and guidelines apt to regulate the relationship between orthodontists and financing third parties, applicable to most western European Countries. The concepts of orthodontic treatment need, orthodontic treatment request and orthodontic screening are discussed, alongside with a short overview of some of the most common indexes to assess the severity of the malocclusion and/or the treatment priority. The screening method introduced by the Danish Ministry of Health is presented; its importance lies in the fact that for the first time a direct correlation between health risk and individual malocclusions is recognized and assessed. In the discussion, it is stressed how the screening system tightly depends on the chosen general model for orthodontic care. Different models of orthodontic care organization as presently used in many European countries are presented and shortly discussed; among these, the Norwegian model is described more in details, because of its simplicity. Eventually, some guidelines considered necessary in order to achieve satisfactory standards of quality and efficiency are presented and discussed.