ABSTRACT
For a long time, injections of foreign substances into the human body have been attempted to correct body defects or to enhance facial aspects.
Various products have been used over the years; many of them were poor and gave severe complications. In 1981, bovine collagen (Zyderm®) was U.S. Food and Drug Administration approved, and since then, lling agents have focused their attention on aesthetic physicians. Since then, many other llers have been launched.
