The prominence of gum tissue on smiling results from the elevation of the upper lip by muscles called the levator labii superioris alaeque nasi. This can sometimes be a source of embarrassment when smiling in front of others. Often people claim to avoid smiling in photos to avoid feeling self-conscious or being unable to fully close the mouth.
What can be done?
Small dosages of Anti-Wrinkle product can simply be injected into the top half of the muscle to relax it allowing it to slightly drop.