Synthetic biomaterials for soft-tissue augmentation and replacement in the head and neck.

Within the next 10 to 15 years, synthetic biomaterials will probably become available that may make many of the polymeric implants discussed in this article obsolete. These new, genetically engineered biomaterials will contain morphogenic proteins capable of directing new tissue growth. We may be able to engage in true "tissue engineering" that allows us to grow a number of tissue types at will, as opposed to implanting bioinert compounds that only mimic the shape of living tissue. Regardless of whether the promise of genetically engineered growth proteins is ever realized, there will be a steady move away from polymeric implant materials that show even the hint of being able to cause cancer or an immune reaction. This movement will result primarily from liability pressure rather than scientific or medical indications. Polymeric biomaterials that are generally regarded as safe now may not be considered safe in the future. The surgeon who implants a biomaterial now may have to deal with a malpractice situation many years after the implant was placed. This is exactly the situation now faced by general plastic surgeons who have used silicone gel breast implants. It is wise, then, to limit the use of these polymer implants in terms of the number implanted and types used. If autogenous tissue is available and will adequately solve the problem, it should be used preferentially. If this is not possible, the surgeon should select only those implants with the lowest potential for future immunologic problems, carcinogenicity, and polymeric degradation over time.