ABSTRACT
Iran has one of the highest numbers of young people in the world; therefore, epidemiologic studies of dento-skeletal malformations in adolescents and young adults are important from population health viewpoints. The purpose of the study was to assess the needs for orthodontic treatment according to Index of Orthodontic Treatment Needs [IOTN] in 14-18 year old students in the city of Shiraz. 1818 students were selected from four districts of education in Shiraz using random cluster sampling. The dental health [DHC] and aesthetic [AC] components of the IOTN were used as an assessment measure of for orthodontic treatment needs. Also, demographic characteristics of the participants were recorded using a questionnaire. The data were analyzed using the student and Chi-squared tests. 60% of the students had no need for orthodontic treatment, 28.4% were in borderline category, and 11.7% showed definite needs for treatment. Also, there was a statistically significant association between malocclusion severity and sex or fathers job or education. 14-18 year old students in Shiraz had better dental appearances and did need less orthodontic treatment than in other populations