A recent trend in body modification in Japan is implanting objects, such as magnets, in the skin.  Now, instead of an actual object being placed in the skin, a saline solution drip is used to cause inflammation and swelling in various parts of the body.  For many, the result is a large, bagel-shaped “implant” on the forehead.  It’s a temporary modification, lasting only around 24 hours or so before wearing off.  Other individuals are placing the saline in the arms, leading to bizarre, disfigured “muscles.”

http://artsyspot.com/bagelheads-new-body-modification-trend-from-japan/