Methods: After taking photos of smile of two female and two male participants, changes were made in “lip line” and “proportion of visible width of maxillary anterior teeth” by computer graphic program (Adobe Photoshop) to provide 9 various modes of these factors for the selection of evaluators. Photos were printed as a questionnaire for evaluation of attractiveness. 20 male and 20 female dental students in their second or third year of education were interviewed and the factors were analyzed according to the results.
Results: Two assessed factors were not independent to be reviewed separately. In upper line, 70% proportion and in average lip line, 62% proportion and in lower lip line, 54% proportion were the most attractive width proportions. Totally, the average lip line was the most attractive lip lines in all width proportions. Gender of evaluator and cases had no significant effect on the rating.
Conclusions: In restorative treatments of maxillary anterior teeth, lip line should be considered before selecting a particular width proportion.