A quick and easy way to whiten teeth in your photos. You can do this in any version of Photoshop.
Open the photo that you want to brighten the smile on. Zoom in to the smile so you can see what you are doing.
Choose the "magic wand" selection tool. Be sure the "add to selection" option is chosen. Click on the teeth to select them. You may need to click in a few spots on your teeth to get the majority of the area selected. It does not have to be perfect. If you get too wide of an area, reduce the tolerance for the magic wand tool.
Now that you have the teeth selected, we are going to simply adjust the hue. In the full version of Photoshop click Image>Adjustment>Hue/Saturation. In Elements choose Enhance>Adjust Color>Hue/Saturation. In the dialog box that opens, next to the word "edit" open the drop down menu and select "yellows". Slide the Saturation slider to the left. You may also have to slide the Lightness slider to the right a tiny bit. Don't over whiten the teeth or they won't look natural.
There you have it. A quick and easy way for you to play dentist and apply a whitening treatment to teeth! Now if it only were that simple on real teeth!