Sientra breast implants were approved for sale in the United States in March 2012

Where do you think the plastic surgery capital of the world is? If you said Hollywood, you would be wrong. It is Brazil.Brazil has been home to many of the world’s greatest plastic surgeons. Their plastic surgeons continue to make some of the most important innovations in aesthetic surgery. And the citizens of Brazil may get plastic surgery more than anyone else in the world.The most popular breast implant in Brazil – and indeed in many other places in the world – is Silimed. In 2007 an American investment group purchased the rights to import Silimed breast implants into the United States, and named the company Sientra. So Sientra does not itself make breast implants; they are an importer and distributor of the Silimed breast implants from Brazil.At the time Sientra acquired the rights to selling Silimed breast implants in the United States, it was in about the fifth year of Silimed’s cohesive implant clinical trial. Sientra took over the trial, and successfully received FDA approval for its round and shaped highly cohesive breast implants in March 2012. They thus became the first and only company to sell teardrop shaped silicone implants in the United States in the modern era (there were teardrop silicone implants available several decades ago.)

click for larger view You may have noticed that Mentor’s gummy bear implants are called the CPG, and that Allergan’s gummy bear implants are called the 410. Why then are all Sientra implants just Sientra?

The reasons are actually unclear to everyone, but it appears to be how the different companies worked within the FDA’s capricious regulations. Allergan and Mentor treated their gummy bear implants as a distinct product line from their standard round silicone gel implants and thus had to have separate FDA approvals for them. But Sientra wisely grouped both their round and teardrop implants together and so they are considered to be the same from a regulatory point of view.

Some have called Sientra’s round implant a gummy bear implant, but in any clinical situation it behaves indistinguishably from the round silicone gel implants made by Allergan and Mentor. And it is quite distinct from a truly gummy bear round implant, which looks round no matter what its position. The Sientra round will alter its shape according to gravity and other forces put upon it. It is not at all form stable.

Shapes of Sientra Breast Implants

Sientra now has five different anatomically shaped implants available. The Classic Base Moderate Projection is their only full height implant, comparable to the four different Natrelle® 410 F height implants and the three different Mentor CPG 3 tall height implants. The moderate projection implant seems to be somewhere between an FL and an FM. But with only one projection available, choices of full height implants are more limited than with the other manufacturers.

Sientra has an oval base implant in three projections – low, medium, and high. Sientra is the only company to have a round base high projecting teardrop implant. This implant was not involved in any clinical trials so there is no data available for it. The projection is extremely high and the footprint is entirely round, so it resembles a breast less than the typical anatomic cohesive implant. Its exact role is as yet unclear.

The Sientra gel is definitely softer than that of the 410, and perhaps more so than the CPG. The shaped Sientra implants maintain their shape better than any of the standard round silicone gel implants (including their own,) but certainly less so than the 410. This is truly a matter of prioritization. The CPG, 410, and Sientra are all equally excellent implants, but each manufacturer chose a different balance of softness and form stability.

click for larger view The surface of the 410 is call Biocell® and it is made by rubbing salt crystals into the outer layer of the shell, and then dissolving them. The surface of the Mentor CPG is called Siltex® and is made by making an impression on it with a textured surface. The surface of the Sientra implants looks more similar to Biocell® than to Siltex®, but the method they use for making it is proprietary. However it is made, it is successful at minimizing Sientra shaped implant rotations to a very low number.

Sientra’s unique distinction

Sientra does make a unique claim that is distinct from the other manufacturers. They call their gel “high strength.” Mentor and Allergan source their gel from one manufacturer, and Sientra from another. It is unclear whether they are using high strength to describe the shell, the cohesiveness of the silicone, or some other property. Whether it is a meaningless marketing term or a description of a unique quality of these implants has not been disclosed.

Some Americans may be wary of an implant being made in Brazil. The Sientra manufacturing facility is inspected by the very same FDA inspectors who also inspect the Mentor CPG production line in Dallas and the Natrelle® 410 production facility in San Juan, Costa Rica. One should also be aware that Brazil is now a first world economy and now makes significant contributions to the world economy.

With the Sientra receiving FDA approval in March 2012, they were the only company selling shaped implants in the United States for all of that year and into 2013. Since only a limited group of surgeons participating in clinical trials were able to use the CPG and the 410 during that time, the Sientra shaped implants became the most commonly used shaped implants in the United States. When the Mentor CPG and the Natrelle® 410 get approved, it will be interesting to see which of the implants become the most popular in the United States.

Most people are amazed when they learn that a doctor doesn’t have to be board certified to do plastic surgery. Sientra took the highly principled position to only sell their implants to board certified plastic surgeons. That of course restricts their sales, but they understood that the results in breast augmentation surgery are mostly dependent upon the surgeon using them. So you can rest assured that if your plastic surgeon is suggesting Sientra implants, that they are a real plastic surgeon. Still, you want to be sure that your plastic surgeon has specific experience using gummy bear breast implants. One other note- look at how round implant on the left standing on its edge looks perfectly round. They may look like that lying flat on a table, but when they are standing upright they fold as seen in the photos toward the end of this section. Their image of this implant is therefore rather misleading. At the same time, you wouldn’t want an implant like that because it would make a breaset that was obviously round and fake.
This advertisement in a plastic surery journal shows the philosophy behind Sientra’s cohesive breast implants, as it says, “Some call the shape and feel of a woman’s breast perfection; we call it inspiration.” The shapes they designed and the gel they chose best replicates what in their mind is the ideal breast. Some would say that the goal of mimicking the feel of the breast should not be the only goal, because softening the gel to do so correspondingly impairs the shape integrity of the implant, which is also an important consideration. It is also possible that a softer implant would be more prone to develop a fold in its shell, so that even if it were more similar to breast tissue in feel, any fold in the shell would be a greater tradeoff in creating the ideal implant. These are very subtle issues, but one that each plastic surgeon will weight differently when selecting a cohesive breast implant for each patient. This ad also demonstrates that Sientra was the first FDA approved shaped breast implants in the modern era.
This ad from a medical journal shows what Sientra itself sees as the highlights of their teardrop breast implant.
On the left is a Sientra round silicone implant and on the right is an Allergan round silicone implant. Note that there are some folds on the base of the Sientra implant. While the Sientra round is billed as highly cohesive, gummy bear, or even form stable, it doesn’t look much different than the Natrelle® implant.

Notice how both the Sientra and Allergan implants lose their round shape when they standon their sides. On one hand that is necessary for them to look like a breast. Were they to maintain their round shape, they would make a breast that looked like a coconut. This is why it is a misnomer to say that the Sientra round implant is a gummy bear. At the very least, it is certainly not at all form stable. It is still an excellent implant, but should be grouped with the standard round silicone gel implants made by Mentor and Allergan.

Viewed also from the top, it is clear that the Sientra round implant is not form stable. It behaves nearly identically to the standard round Allergan implant on the right. And a standard round Mentor MemoryGel® implant would behave just the same.

On the left is a 410 FM (full height-moderate profile) and on the right is a Sientra classic base moderate projection implant. The shapes are fairly similar, but notice that there is a little bit of a buckling on the Sientra, but not on the 410. That is an inevitable trade-off with using a softer implant. Once inside the body, the pressure and support of tissues will change the degree of collapse to some unpredictable extent. Plasitic surgeons will put different relative values on the greater form stability of the 410 v the greater softness of the Sientra breast implants.

When lying flat, it is obvious that the 410 on the left and the Sientra on the right have different shapes. A surgeon’s preference for one over the other is based upon their own perspective as to which shape would best fulfill a particular patient’s request given her anatomy.

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