Body piercing, which is a form of body modification, is the practice of puncturing or cutting a part of the human body, creating an opening in which jewelry may be worn, or where an implant could be inserted. The word piercing can refer to the act or practice of body piercing, or to an opening in the body created by this act or practice. It can also, by metonymy, refer to the resulting decoration, or to the decorative jewelry used. Piercing implants alter body and/or skin profile and appearance (e.g. golden threads installed subdermal, platinum, titanium or medical grade steel subdermal implants). Although the history of body piercing is obscured by popular misinformation and by a lack of scholarly reference, ample evidence exists to document that it has been practiced in various forms by multiple sexes since ancient times throughout the world.