RESUMO
Objective: This study was conducted to evaluate the perception of midline coincidence as a determining factor in smile aesthetics. Methods: A single of a female smile was intentionally altered with a software program (Adobe Photoshop, CS5. 1990-2010, Adobe system incorporated). The alteration involved shifting the upper midline by 0.5mm to the left in four variations. These altered images were then rated by two groups, 30 in each group, the professionals and the lay persons using a visual analogue scale. Results: There was a statistically significant difference between the professionals and the laypeople in the perception of midline coincidence as a factor in assessing smile aesthetics, (p=0.038, T=2.1). Conclusion: The orthodontists, general dentists, other professionals and the laypersons detected specific dental aesthetic discrepancies at varying levels of deviation