How to Whiten Teeth in a Portrait

Step 1 – Locate the teeth with Quick Mask

First we need to select the teeth so nothing else in the frame is affected. A Quick Mask is the simplest and most direct way to do it.

1. In the Layers panel on the left, press Ctrl+J to duplicate the Background layer (so the original stays untouched).
2. Click at the very bottom of the toolbar to enter Quick Mask mode.
3. Make sure the foreground color is black and the background color is white.
4. Press Ctrl+Backspace (⌃+Delete on Mac) to fill the whole canvas with red, which means nothing is selected yet.
5. Switch to the Brush tool (B), change the foreground color to white and set the options bar as follows:
   • Opacity 41 %
   • Flow 46 %
   • A soft-edged brush (round soft is recommended)
6. Brush over the teeth to wipe the red away — the areas painted white become the selection.

When you are done, click the Quick Mask icon again to leave Quick Mask mode. Online PS converts the white areas into a standard selection automatically.

Step 2 – Turn it into a selection and a mask

Leave the selection as it is and create a mask on the duplicated layer, so the following color work only touches the teeth.

1. Confirm the selection is still active (the marching ants flicker around the teeth).
2. Click the Add Layer Mask button at the bottom of the Layers panel (the icon with a circle inside a rectangle).

The mask now hides every pixel except the teeth, so all the color adjustments that follow affect the teeth only.

Step 3 – Brighten the teeth with Curves

Curves is the brightness and contrast tool you will reach for most often in Photoshop. Start by lifting the teeth as a whole.

1. Make sure the "Background copy" layer with the mask is selected.
2. Press Ctrl+M (⌃+M on Mac) to open the Curves dialog.
3. Click once on the curve to add a control point (slightly left of center works well), then drag that point up so the curve forms an "S".
4. Fine-tune as needed: if the teeth still look dull, raise the upper-left point a little so the shadows get brighter; if they look too white, lower the right-hand point slightly.
5. Click OK and the teeth are noticeably brighter.

A slight yellow cast usually remains, and that needs a more careful pass.

Step 4 – Finish with Hue/Saturation

Use Hue/Saturation to target yellow specifically and remove the last of the yellowing.

1. Confirm the same layer is still selected.
2. Press Ctrl+U (⌃+U on Mac) to open the Hue/Saturation dialog.
3. In the dropdown at the top-left of the dialog, choose Yellows.
4. Drag the Saturation slider left to -30 to reduce the yellow.
5. Drag the Lightness slider right to +100 to make the teeth whiter.
6. Confirm, and the teeth should now read as near-white with no obvious yellow stain.

When you are finished, don't forget to save with Ctrl+S (or File → Export As → PNG/JPEG).

Tips & pitfalls

• Keep the original layer: duplicating the Background at the very start (Ctrl+J) means you can always get back to the original.
• Brush opacity: a low-opacity brush lets you trace the shape of the teeth more precisely and avoids catching lips or gums by mistake.
• Zoom in: Ctrl++ (zoom in) and Ctrl+- (zoom out) help you paint a more accurate selection.
• Don't overdo it: teeth that are too white look fake. Lift the brightness during the Curves stage first, then fine-tune with Hue/Saturation.
• Compare before and after: at any point you can Alt+click the mask to hide it, or Ctrl+Z to undo, and see the original against the edited version.