Aim: To describe the results of a cross-national survey of orthodontists’ preferences regarding initiating treatment at various dentition stages. Previous research has demonstrated high acceptance of early intervention by parents and children, and, in many cases, better compliance with treatment protocols among younger children than among adolescents. Methods: The current study questioned orthodontists in three countries. The identical survey, translated from English to Turkish and Italian, was administered to 137 American, 104 Italian, and 62 Turkish orthodontists. These orthodontists represented a wide cross-section of their specialty in years of experience, gender, and type of practice. Results: The three groups agreed on the ideal dentition stage only for some occlusal and skeletal conditions. The Italian sample was most likely to intervene at the youngest age for 14 of the 41 conditions, whereas American orthodontists chose treatment at a significantly younger age than the others for 10 conditions. For most conditions, Turkish orthodontists tended to postpone treatment longer than the other two groups. Italian orthodontists reported more 2-phase treatment than either of the other two groups; 1.6 times more than Americans and 1.9 times more than Turkish orthodontists (P
.001). American and Turkish orthodontists reported that their most frequently treated age group was teens (44.4% and 46.5%, respectively), with less than 10% aged 6 to 8 years. In contrast, Italian respondents reported an average 17% caseload in the youngest group (P
.001). Conclusion: The results highlight variations in treatment philosophies, despite extensive international communication among orthodontists. World J Orthod 2004;5:40–47.