Do facial exercises actually work or make your wrinkles worse?

There is plenty of information about face exercises, but is there any scientific evidence that exercises for the face are really effective?

No, as far as I know, all we have is the testimonials of many people who believe they work.

Update: A small study carried out by Jama Dermatology found that women who practiced facial exercises for 20 weeks looked 3 years younger. You can read the article in The New York Times.