Much has been made of the news a couple of weeks ago that the FDA approved a type of implant commonly known as “gummy bear” or “anatomic” style (specifically, Allergan style 410; another version from Sientra has been available in the U.S. for almost a year.) Their teardrop profile and variety of shapes lead many to consider them superior to the round implants that were formerly available. But are they really better? Here I will outline the plusses and minuses of each type, but remember that a personal consultation is recommended before making a decision.
First some terminology: Medical grade silicone gel used in breast implants is cohesive, meaning that it holds together as a semisolid mass; this is true for both round implants and gummy bear implants. However, the gel used in the new implants is firmer, so it holds a shape as for example gelatin would (or a gummy bear.) The gel in round implants is softer, so it may behave more like a natural breast in that it will be more round when horizontal and more of a teardrop profile upright. For this reason the new implants are most accurately termed “form-stable” or “shaped”. This property makes them well suited for breast reconstruction where the implant has to create the shape as well as restore the missing volume after mastectomy.
An important feature of shaped implants is that they must maintain the correct orientation, because any degree of rotation will create a deformity. So the implant surface has a rough texture, designed to enable the body to adhere to it during the healing phase. In order for this to occur, a suction drain tube is necessary to prevent any fluid from collecting around the implant. A final difference is that a longer incision – hence a longer scar – is required to place form-stable implants as compared to round implants. Most of the time this is along the bottom fold of the breast.
So while there are some cases where a form-stable implant will give a better result, it certainly isn’t for everyone while there are some cases where a form-stable implant will give a better result, it certainly isn’t for everyone.
See an example of a revision breast reconstruction with form-stable Sientra implants here.
| Shaped | Round | |
| Feel | Firmer | Softer |
| Rotation deformity | 2-3% | None |
| Scar | Longer | Shorter |
| Drains required | Yes | Not usually |
| Surface | Textured | Smooth or Textured |
| Cohesive gel | Yes | Yes |
