Breast implants are nothing new in Hollywood. Some stars willingly reveal that they've had them, either to boast, get attention, or just plain get the truth out there and avoid all the stories. Some stars get them and neither confirm or deny it despite the obvious differences. And other stars don't have them, yet constantly become the objects of speculation because of an outfit they wore that either made their bust look bigger or smaller.

To the untrained eye, when a star wears a low cut gown that's tight on the sides basic physics applies and things "get pushed together", giving the appearance that things are much larger than they actually are.

Going braless and wearing a loose shirt can cause the opposite (some even say 'OMG, she's anorexic!').

But with so many different pads and push-ups on the market it's getting difficult to tell whose had breast implants or not.

There are a few stars who have even had them and then had them removed, and a couple others who had them, had them reduced, and then had them enlarged again.

After the jump: our list of stars who have had implants (we think), based on confirmation from the star or their surgeon (Heidi Montag), the obvious (Kellie Pickler), or just common knowledge (Pamela Anderson)...