Invented by Mrs. E. Isabella Gilbert in 1936 (although I think similar gadgets had been on the market before). They came with these instructions: "Wear dimplers five minutes at a time, two or three times a day, while dressing, resting, reading or writing. Look into the mirror and laugh. There will be a semblance of a line where you should always place the dimplers until your dimples are made."
According to History By Zim
: "The American Medical Association argued that the 'Dimple Maker' would not make dimples or even enlarge original dimples. They also stated that prolonged use of the devise may actually cause cancer."
Louisville Courier-Journal - June 19, 1937
Battle Creek Enquirer - June 19, 1937
Detroit Free Press - Aug 9, 1936
Medford Mail Tribune - Nov 22, 1936
I was curious to know when exactly the American Medical Association denounced the Dimple Maker, since the History by Zim blog didn't mention a date. I tracked it down to 1947, when the AMA put together a collection of quack medical products that it displayed on a nationwide tour of museums.
The Philadelphia Inquirer - Jan 11, 1948