When you picture Ben Affleck, Miley Cyrus, and Gwen Stefani, they don’t appear to have much in common. However, all three celebrities have a ‘gummy smile’ (or had one before they had cosmetic procedures to fix them). In the dental world, this is called excessive gingival display. It occurs when an above average amount of the gum can be seen when smiling. The generally accepted magic number is 3mm. Anyone with more than 3mm of gum showing when they smile could be labeled as having an excessive gingival display.