Eva Mendes, one of Hollywood’s great beauties, was an ugly duckling as a kid. “I had the nickname Bugsy, for Bugs Bunny, because I had buck teeth,” she told Webster Hall’s Baird Jones after a screening of “Live!” a mockumentary about an ambitious TV exec producing a reality show in which contestants play Russian roulette. “I still have buck teeth, but then I was only like 70 pounds, so they really stood out. I never got braces because I am OK with my imperfections. In fact, I like to accentuate my buck teeth when I smile. I just have a big old smile. I never cover my mouth.”