There are two main types of smile:

• Le static smile, which can be repeated and reproduced on request by the individual. It is particularly found when photographing subjects. It is easily recognizable by its commissural aspect.
• Le spontaneous smile, which is not reproducible and which is situation-dependent. Dynamic and explosive, it reveals a maximum of teeth and is accompanied by several observable changes of the face.

For many centuries, teeth were completely absent from works of art showing smiling faces. The Mona Lisa by Leonardo da Vinci perfectly illustrates this surprising observation, applicable to all statues, frescoes or paintings.

The arrival of photography seems to redraw the smile by giving it the white teeth that make it so radiant. Quickly, the “toothed” smile becomes the symbol of youth, beauty and seduction. Today, it is omnipresent in posters, advertisements and photographs, and it is displayed as a powerful vector of success, health and seduction.

For the French sociologist Jean-François Amadieu, beauty is clearly a factor of success. A study conducted by the O’Doherty team shows that we would be more inclined to listen to a person who seems attractive to us, which validates a quote from Montaigne: ” Better a well-made head than a full head ».

However, it is undeniable that the face is one of the most important criteria as regards attractiveness, the mouth being, moreover, cited first among the various elements of the face.

But, what would be the most attractive smile? For Francis Bacon, “ the quest for beauty is universal, but its judgment is marred by subjectivity », In other words, aesthetics have a great subjective dimension.

Le dentist, nevertheless, it is necessary to know the objective criteria allowing to optimize the esthetics of the corrections and dental prostheses. These supposedly objective criteria are in reality dependent on the society and the culture in which they are inserted.

Thus, Western society emphasizes the toothy smile, while in some Asian societies, black lacquered teeth represent a real criterion of beauty. In Nigeria, the diastema, this gap between two teeth, is perceived as an asset of seduction. However, apart from these few exceptions, it seems clear that Western society has imposed its aesthetic vision of smiling almost everywhere in the world.

Studies show: People with healthy, white, aligned teeth are seen as more attractive. Social rules emerged and brought the orthodontists to define objective smile beauty criteria.

Research has been carried out to guide prosthetists and dentists in their practice.

– The modern smile is toothed or dento-labial (of which we only see the upper teeth, for example). It is a smile in which the teeth are widely visible.

– The upper teeth (jawbones) must be aligned in a curved line down the middle, and upward at its ends.

– The teeth of the smile must compete with the arc of the smile, parallel to the edge of the lower lip.

– The smile should show all of the upper incisors and not the lower incisors. The latter are more and more apparent with age. “The appearance of the upper incisors corresponds to youth; the appearance of the lower incisors corresponds to old age ”said Professor Zachrisson.

Repeated facial movements and their degree are likely related to the degree of facial wrinkles: in other words, the more you smile, the more faces you make and the greater the risk of being wrinkled quickly.. Moreover, during a study, the shape of wrinkles could be predicted at the age of 8 years only based on his facial expressions. Observe what happens when you smile or frown: some lines appear more pronounced. These are called dynamic wrinkles. Over time, they are more likely to become static wrinkles, that is, lines visible even when the face is void of expression. Several factors such as sun exposure or lifestyle will then influence the speed of the process. But can we reasonably deprive ourselves of smiles when we know all the virtues they bring?

While we tend to think that a smiling and expressive face makes you look younger, a study has just shown the opposite. Smiling could change the way a person is viewed, especially their age. The study participants consistently gave smiling faces older ages compared to the same expressionless faces. This would be linked to the highlighting of expression lines, especially in the eyes and lips.