**1. Introduction**

The public's demand for facial beauty has increased over time. Different cosmetic procedures have been introduced to meet this demand. The essentials of facial cosmetic surgery are: 1- Volume replacement and 2- Facial augmentation. Better aesthetic results have been achieved by using less invasive surgical techniques including lifting procedures, injectable fillers, autologous fat transfer, and facial implants.

The malar eminence and chin are the most common facial sites augmented via implants. Autologous tissues have been the gold standard for facial augmentation for years; but today alloplastic materials are more commonly used.

Drawbacks of autogenous grafting include: donor site morbidity, limited availability, limited moldability, and unpredictable resorption [1].An ideal alloplastic implant must be made out of a material that has low bioactivity or toxicity. It must also be stable and biocompatible [2]. An understanding of these qualities is needed to prevent complications or to treat them should they occur.
