Every once in a while, we notice there's something different about the appearance of one of our favorite celebs. While the cause is often something as simple as a change in weight, sometimes these tweaks can be attributed to plastic surgery.

It's largely unconfirmed whether celebrities have gone under the knife, but we gathered pics of our favorite stars who have supposedly had work done. What do you think -- did they get a nip and tuck?

See the before and after shots in the gallery above!