Were excluded dental students and dentists.
Each interview was transcribed and coded in order to make an explanatory model by the method of Grounded Theory.
Results: The study establishes that both groups interviewed valued the smile as an expression denoting positive feelings, being an important feature in the face, especially in adults. However, there are differences between the groups regarding preferences and requirements of a beautiful smile. Conclusion: The smile as facial expression is an important feature especially in young people and adults, feature influential in the perception of facial attractiveness and beauty. Women are associated with this facial expression, while men more serious expressions.
Among the constituent elements of a beautiful smile, both groups agreed to have all the teeth, but they differ in young people is essential tooth alignment, whereas for adults is more important the color of the teeth.