According to a newly released study in the Journal of the American Dental Association, the smile is the most important attribute in regards to facial esthetics among the general population. The study participants indicated that a person’s teeth are the most important aspect in determining facial attractiveness. In this random study, teeth were the #1 factor that people used to determine the attractiveness of another person followed by eyes, skin, hair, lips, nose, etc.--see attached tables below. This university research suggests that the greater the misalignment of a person’s teeth, the lower their facial attractiveness score. Accordingly, a person stands to lose more in their facial attractiveness rating due to malocclusion than any other facial feature. Ratings varied slightly between men and women.
Here's the latest research which talks about how straight teeth can be healthier for your body too!