New York Post may receive revenue from affiliate and advertising partnerships for sharing this content and/or when you make a purchase A picture says a thousand words, but a smile says a million.

While we are all born with different shades of enamel, our teeth yellows over time for a variety of reasons, some of which you may not have even realized are contributing to your "yellowing" smile.

A new study shows the glow from tooth whitening often fades within a year, but whether you still love your smile may depend more on your personality than the shade of your teeth. Study: Effect of ...