Draw an imaginary horizontal line through the centre of both your pupils and another horizontal line between the tips of your canine teeth. Ideally, these two horizontal lines should be parallel. Often, one side slopes down.
Draw an imaginary vertical line through the centre of your face. This mid-line should run through the centre of your eyes, nose and chin. Ideally, the mid-line should also run through your two central incisors thus making the central incisors a mirror image of each other.
Ideally, a wide smile will show your first molar to first molar tooth. Although if you have a narrow smile you may only see the front six teeth from canine to canine.
Draw an imaginary curve along the bottom of your upper teeth and compare it to an imaginary curve of your lower lip. Ideally, your smile should be curved in order to look younger.
Draw an imaginary curve along the top of your upper teeth. Ideally, only the pink triangular parts of gum between the teeth show. However, some people show a lot more gum or the gum that shows is uneven giving an irregular gum line.
The Golden Proportion
This special proportion was discovered by the Greeks and is found in many areas of nature. Ideally, the widths of each of the front teeth compared to the next follows this special proportion.
Ideally the width of a tooth should be approximately 80% of the length. However for patients that wear/grind their teeth, this ration is closer to 1:1 as the teeth have shortened and become squarer. This is a way to measure exactly how much tooth has been lost over the years and is often used to rebuild edges of teeth to their ideal proportions and perfect smile.
These are the little triangular like spaces between the tips of the front teeth. Without embrasure spaces, the teeth would look like flat piano keys with no character to them. Ideally, the embrasure spaces should be smallest between the two central incisors and gradually become larger as you examine teeth further into the mouth. An ideal feminine smile tends to have more definite round embrasures.