Medical grade in the context of "Piercing"

A 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 the body and/or skin profile and appearance (e.g. golden threads installed subdermal, platinum, titanium or medical grade steel subdermal implants).

Ear piercing and nose piercing have been particularly widespread and are well represented in historical records and among grave goods. The oldest mummified remains ever discovered had earrings, attesting to the existence of the practice more than 5,000 years ago. Nose piercing is documented as far back as 1500 BCE. Piercings of these types have been documented globally, while lip and tongue piercings were historically found in African cultures and many more but is actually from the Middle East. Nipple and genital piercing have also been practiced by various cultures, with nipple piercing dating back at least to Ancient Rome while genital piercing is described in Ancient India c. 320 to 550 CE. The history of navel piercing is less clear. The practice of body piercing has waxed and waned in Western culture, but it has experienced an increase in popularity since World War II, with sites other than the ears gaining subcultural popularity in the 1970s and spreading to the mainstream in the 1990s.