09/07/2015                                                                            
                                    
                                                                            
                                            Injectable soft tissue fillers
INTRODUCTION — Soft-tissue fillers can be used alone or in combination with other aesthetic procedures to correct wrinkles and to restore tissue volume lost due to aging, lipoatrophy, or other causes. As opposed to permanent fillers, which persist indefinitely, temporary fillers are eventually resorbed by the body. Some agents, such as injectable collagen and hyaluronic acids, function primarily through a volume-filling effect. 
The type of defect to be treated and the desired duration of effect influence the selection of a soft tissue filler. 
HYALURONIC ACID — Hyaluronic acid is a naturally occurring glycosaminoglycan that is an essential component of the extracellular matrix of the dermis. The molecule plays a key role in the maintenance of skin structure and function, and its high water-binding capacity is of value for the maintenance of moisture in the skin. 
The injection of exogenous hyaluronic acid into the skin effectively reduces visible signs of volume loss, while simultaneously providing a natural look and feel after treatment. These features, plus a relatively low risk for adverse effects have made hyaluronic acid-based fillers the most commonly used injectable soft tissue fillers worldwide.  Although the US Food and Drug Administration (FDA) has approved hyaluronic acid fillers only for the treatment of nasolabial folds, these products have been used for a variety of other indications, including marionette lines, glabellar rhytides, age-related volume loss in the dorsal hands, and augmentation of the lip, chin, and cheeks. The clinical effects of treatment typically persist for 6 to 12 months.
Source: Uptodate