Many people feel that all that is necessary to have a very attractive smile is to just have straight white teeth. Research has shown that a great smile involves much more that just those two things. To be sure, a great smile can be helped by having the teeth be straight and white, but when people who are not dentists are asked to evaluate smiles, however, they actually are considering a good number of other thing besides straightness and whiteness—althought they likely do not realize it. When people are given a chance to evaluate other factors through well designed scientific studies, it is interesting to find that they are evaluating a number of other variables in the smile.
One thing should be understood at the onset, and that is that people have two different smiles depending on the circumstances. They display the “social smile” under some circumstances and the other smile they may display other other circumstances is the “elation smile”. The “social smile” is a voluntary smile under the person’s control when a person is just posing in a manner in which they feel their smile looks the best. The “elation smile” is when a person is truly joyous or truly excited and flashes the biggest smile on an involuntary basis
A list of some of the things that matter to people in a smile—again, they generally do not know that they are specifically evaluating them in most cases but dental research indicates that their mind is processing the following variables of the smile:
– The amount of upper gum tissue that is exposed in the smile. Most studies show that the great smile is one in which the upper lip covers the the upper front teeth by about 2 mm (the thickness of a quarter). If the lip lifts and displays more than 3mm of gum, it is considered in most cases to be a relatively unfavorable smile. Also, it should be realized, if the lip upon smiling covers the front teeth by more than 4mm it is considered less than ideal as well.
– The smile arc is “correct”. The smile arc is relationship of the curve that is created by the lower lip in the smile and the relationship of the upper front teeth and the upper back teeth to that curve that is created by the curved lower lip in the smile. Generally, as the lower lip curves upward, the upper back teeth should pretty much follow that curve. in other words, the great smile should not display too much gum in the back of the mouth— just like the great smile should not display too much gum tissue in the front of the mouth(see above).
– The cant of the occlusal plane should be level. This means that when the smile is viewed from the front, the teeth should not be sloping downward or upward on either side, but be even straight across.
-The front teeth should be properly proportioned. That is, the width of each front tooth should be about ¾ of the height of each tooth
-The midline should be correct. This means the middle of the upper front teeth should not deviate more than 3mm to one side or the other.
-The buccal corridors should not be too big or too small. The buccal corridors is the gap between the corners of the mouth in the smile and the back teeth—they are black spaces because light cannot fill those voids when the person is smiling. They should be about 11mm (a little less than a half inch) wide on each side If they are too big the dental arch appears too narrow, and, if they are too small the dental arch appears too wide.
There are other factors that determine if a person has a great smile, but the above variables are the principal subtle controlling factors, besides the color and straightness of the teeth, that affect the favorable esthetics of the smile.