From: Daniel Piechnick
Hi AirBro_Ron Sears. Just remember to brush daily. Flossing can help too. :) The best way to make someone's teeth whiter in Adobe Photoshop would be to select their teeth with the Freeform Pen Tool, and then go Image > Adjust > Brightness and Contrast (or press Ctrl+U for the Hue and Saturation slider). Increase the brightness of the area. In the Hue and Saturation slider, select Yellows from the menu, and decrease the saturation. I'm not sure about your subject's teeth, but yellow is probably the most offending colour, and reducing its saturation should help remove it a bit. Check out the "Separating an Image from its Background" tutorial at http://www.pegaweb.com/tutorials/separation/separate-image-from-background.htm for information on how to select the exact area of their teeth.