Differences in the perception of needs and demands for orthodontic treatment between Koreans and Japanese

The objective of this study was to determine the differences in the perception of the needs and demands for orthodontic treatment between the members of two different countries, Korea and Japan. Based on 10 representative malocclusions, a questionnaire survey was carried out in patients, dental students, and orthodontists from Korea and Japan. After showing the participants frontal, lateral photographs along with the orthodontic casts of the 10 selected malocclusions, the "Needs for Orthodontic Treatment (NOT, 10-point VAS scale)" and the "Demands for Orthodontic Treatment (DOT, yes or no question)" of each malocclusion were scored by the participants. As the result, high needs and demands for orthodontic treatment were associated with severe skeletal and dental discrepancies in all three groups from both countries. In other malocclusion cases, the Patient group indicated lower needs and demands compared to the Orthodontist group while the Dental student group scored an intermediate value. Interestingly, Koreans tended to score higher needs for class I, class II and deep bite malocclusion compared to the Japanese, while reversely they scored lower needs and demands for class III and openbite malocclusion. Overall, it is important to recognize the discrepancies in the perception of malocclusion between different ethnic groups even in neighboring countries as well as between patients and orthodontists of the same racial/ethnic background.