Some people feel this way:

I used to cover my mouth whenever I smiled or laughed, I actually made a conscious effort not to laugh or smile, it was pretty sad actually. I have a hard enough time with my self-image and this definitely wasn’t helping. I am not proud to have top dentures at such a young age but only the people who I tell or who know me even know they aren’t my own. I did this a few months before I got married, and have no regrets. It was so nice to be able to smile again without feeling extremely self conscious.