In your 20s, you have slight ridges on the surface of your teeth and tiny ripples at the bottom of your teeth, that give dimension, character and youthfulness to your teeth. Over time, teeth shift and shorten causing your lips to sag inward. The edges and surfaces flatten causing a boxy appearance. Grinding further exacerbates this process. It is possible for your front teeth to be as much as two millimeters shorter by the time you reach your 40s. In addition, thinning enamel and years of wear can cause fine cracks that are more susceptible to staining
New crowns create a younger appearance by reestablishing the proper tooth form.