Dominant Upper Central Teeth:

Upper two front teeth should be wider and longer than the teeth next to them, and about the same length or longer than the "eye" (or "canine") teeth.

Young Smiles Show Longer Centrals:

When the lips relax a bit of the centrals still shows, especially in a young smile. Shortened upper centrals give a worn and therefore older appearance

Edges Of Lower Teeth Follow The Lower Lip:

The edges of the upper teeth follow the curvature of the lower lip. Teeth that are too level or centrals that are shorter result in a "reverse smile line" which looks aged.

Just A Little Gum Shows:

Only 1/16 to 1/8 of an inch of gum should be visible in an ideal smile. When more gum shows the smile looks "gummy".

Visible Back Teeth:

The back teeth should be visible to fill out the arch. If only the front teeth show it looks as if teeth are missing

Straight Profile:

In profile the teeth should support the upper lip, but be straight. If teeth are positioned too far out it pushes the upper lip up and out, if teeth are too far in everything sinks, both cases negatively affecting the profile