Introduction to Permanent Fillers: Pros and Cons

Introduction

In the past 15 years, there has been a dramatic increase in the use of injectable facial fillers for rejuvenation of the aging face. With more than 2.7 million soft tissue filler procedures performed in 2019 in the United States, there has been increasing interests in research and development of both temporary and permanent agents. There is no universally accepted classification for soft tissue fillers; however, they can be classified by their origin—natural animal, synthetic, or natural synthetic. They can be further classified by their longevity: temporary, semipermanent, or permanent. An ideal soft tissue filler is one that is effective; easy and painless to inject; feels natural; is nontoxic, nonreactive, noncarcinogenic, and nonimmunologic; has a low incidence of adverse events; and is long lasting. The US Food and Drug Administration (FDA) defines permanent fillers as materials that are composed of nonabsorbable or permanent materials. These agents can provide excellent, long-term results but carry more potential risk and require a higher level of injector skill given that complications are more common compared with temporary agents and can be more difficult to resolve. In the United States, the currently available permanent fillers are polymethylmethacrylate (PMMA) and liquid injectable silicone (LIS), but only the former is approved by the FDA for the correction of nasolabial folds and moderate to severe, atrophic, distensible facial acne scars on the cheek in patients over the age of 21 years. Several other agents are available for use outside the United States or are currently being developed ( Table 13.1 ).