Studying the face’s symmetry and drawing the axes are the beginning of the design in dental aesthetics in order to obtain the ideal smile.
In 80% of the cases the fixed points to find out the symmetry of the face are the eyeballs. Only if the topography of the eyes is not symmetrical the lacrimal glands or ear flaps are taken into consideration.
There are cases when an average between the lines that unite the two pairs of symmetrical points is recommended.
Another fixed point in designing the position of the teeth is the curve of the upper lip’s edge when smiling. The teeth must be placed according to the edge of the lip, so when smiling, a symmetrical proportion of the surfaces can be seen.
The shape of the lip’s edge when smiling is gradually transformed from a straight line into a curve.
Some studies classify the shape of the smile’s curve in 4 categories, being correlated with the patients’ personality: phlegmatic, choleric, sanguine, melancholic.
Being guided according to the facial axes and the smile’s curve guarantees the precision of the teeth’s design in prosthetics, repositioning in orthodontics and surgery according to aesthetic principles.
Thus, dental aesthetics and the beauty of the smile is mathematically dictated by the link between the facial axes and the curve of the smile.