British orthodontist R.J. Edler cited research supporting the claim that "bilateral facial symmetry is an important indicator of freedom from disease, and worthiness for mating. Random differences between the two sides, known in biological terms as 'fluctuating asymmetry', develops throughout the lifespan of the individual.
Experimentally, when the shape of facial features is varied, increasing symmetry of face shape increases ratings of attractiveness for both male and female faces. These findings imply facial symmetry may have a positive impact on mate selection in humans."
I'm not so sure about that!