Evaluating the relationship between Orthodontic Treatment need and Oral Health-Related Quality of life Among students aged 15-18 year in Shiraz

The major demand for orthodontic treatment is associated with esthetic complaints rather than with the severity of occlusal irregularities. This study evaluated the relationship between orthodontic treatment need based on index of complexity, outcome, and need (ICON) and orthodontic- specific quality of life (QOL) among high school students in Shiraz. Materials and methods: Based on the correlation between ICON and QOL score (r = 0.254) with α = 0.05 and an estimated power of 80%, 118 high school students (49 girls and 69 boys) aged 15-18 years were selected for this analytical cross-sectional study. The students were randomly selected. The need for orthodontic treatment was determined according to ICON and was compared with QOL, which was assessed using Cunningham’s questionnaire. Data analysis was performed by SPSS-21 using Spearman’s correlation coefficient and Mann-Whitney tests. (p<0.05) Results: Analysis based on Spearman’s correlation coefficient, showed no significant association between QOL score and ICON (r=0.95, p=0.282), Mann-Whitney test did not show a significant difference between boys and girls. QOL score was considerably higher in boys (median = 18.50, mean ± SD = 14.82 ± 18.5) compared with girls (median = 9.00, mean ± SD = 14.3 ± 15.02) (p = 0.58). Conclusion: No significant difference among boys and girls in relation to orthodontic treatment need was observed, although girls had a significantly lower QOL score than boys. Correlation between orthodontic treatment need and its impact on QOL was also not significant. Therefore, dental esthetics has a greater impact on social acceptance and self-concept among girls. Key words: •Index of Orthodontic Treatment Need •Quality of Life •Students