ABSTRACT
A paramount objective of modern orthodontic therapy is the improvement of facial esthetics. Orthodontic treatment can cause an attractive smile through change in position of the anterior teeth. Thus the purpose of this study was to determine the standards of the beautiful smiles and also the effects of non extraction orthodontic treatment on smile esthetics. Sixty three women, 30 with non extraction orthodontically treated occlusions and 33 with normal occlusion were selected. Five standardized black and white close- up image of their posed smiles were taken and then the most natural photograph of each case were selected. At next selected photographs were evaluated by a panel of five men and five women of varied vocations. They were told to rate each photograph as to the attractiveness of the individual smile with visual analogue scale. This study showed 27.3% of normal occlusion females with out history of orthodontic treatment had very good, 57.6% had good and 15.1% had fair smiles. But in none extraction orthodontically treated group 10% had very good, 76.7% had good and 13.3% had fair smiles. As the result of the panel members evaluations, orthodontically treated subjects and subjects with normal occlusion had similar smile scores. Furthermore smile line ratio, buccal corridor ratio and symmetry ratio were not significantly different between two groups. On the other hand, there were no significant difference in smile morphometric indices between fair, good and very good smiles. This study demonstrates that the smile line, buccal corridor and symmetry of smile do not influence smile esthetics and also orthodontically treated subjects and subjects with normal occlusion had similar smile esthetics