Assignment and compression of facial index and modified smile index (MSI)

Aim: Ideal facial esthetic and smile as one of it's components are the major topics in orthodontic treatment. One important goal in modern orthodontics is harmony between facial soft tissue in static and dynamic state. The objective of this study is evaluation of correlation between facial index and modified smile index (MSI). Materials and methods: This study was a descriptive-cross sectional study. ۱۳۰ patients who referred to orthodontic department of dental faculty of Yazd shahid sadoughi university of medical science were chosen. The facial index of subjects were determined on the basis of Farkas study as (N’-Gn’÷Zy-Zy ×۱۰۰). Then photographs of their social smile from frontal view were captured and inter commissural distance (IC) and inter labial gap(ILG) were also measured and MSI was determined as [(ILG÷IC)×۱۰۰]. By using SPSS software and statistical analysis (T-test and Pearson correlation) mean value of MSI and facial index was attained in men and women and The correlation rate between facial index and MSI was also evaluated. Results: The results of statistical analysis (T-test and Pearson correlation) showed that: The facial index mean value was ۱۰۷.۶۸±۷.۱۵ (۱۰۸.۳۹±۷.۲۶ in men and ۱۰۶.۹۸±۷.۰۳ in women).there was no statistical difference between ۲ sexes. (Pvalue: ۰.۲۶۵) The MSI mean value was ۱۷.۷۶±۳.۷۹ (۱۷.۳۳±۳.۷۵ in men and ۱۸.۱۹±۳.۸۰ in women).there was no statistical difference between two sexes.(Pvalue:۰.۱۹۸) There was no statistical correlation between facial index and MSI (Pvalue:۰.۹۲۰).Conclusion: There are different faces and MSI but there is no correlation between facial form and smile type.

Keywords:

Facial index , MSI , esthetic