Sientra shaped round HP 425cc or Natrelle 475cc style 20? (photos)

Had my pre op on Monday and now I'm more confused on what size to get since my bwd is 12.5 were trying to stay under 13. The sientra HP shaped ones only go up to 425cc doc only had 375 for me to try on and those were to small he didn't have the 425 to try, now I'm leaning towards the natrelle 475cc round HP style 20 implants. He said I have up till the surgery date to decide which is the 19th. he said don't compromise how big I want to go just to get the "gummy bears" suggestions appreciated!

Doctor Answers 11

Sientra shaped round HP 425cc or Natrelle 475cc style 20?

In my opinion, the biggest difference between shaped and round implants is the fullness in the upper pole of the breasts.  If you want a more full look in the upper pole, go with the 475cc round implants.  If you want a more natural look in the upper pole, go with the 425cc shaped implants.

Don't get hung up on the term 'gummy bear'.   It not a real term and is used so many different ways that it isn't even really clear what it means anymore.

Chevy Chase Plastic Surgeon
5.0 out of 5 stars 28 reviews

Shaped textured implants vs. smooth round implants?

Thanks for using one of our patients as your goal photo (first one on the left). But your third goal photo shows a woman wearing a push-up bra giving her a high, round, Baywatch coconut look. That is the effect of the bra, not the implant.

You do not need shaped implants since smooth round implants are teardrop-shaped when standing up, and flatten and round out when reclining, just like natural breasts do. Form-stable implants remain teardrop shaped even when reclining, which is decidedly NON-anatomic! Further, textured implants adhere to tissues, and therefore do not move as naturally as smooth round submuscular implants do.

I'm also a bit concerned that your surgeon doesn't offer all sizes to try on. Does this mean he has to order implants in advance of surgery? In our surgical facility we stock multiples of each implant size and each implant profile, so they are always in stock and we never have to tell a patient "Sorry, we didn't have that size available."

That being said, I agree with his comments about sizing--50cc is 3 tablespoons and 1 teaspoon (not a lot, and not even a visible difference in most cases.

But yet he also allowed a misconception about silicone cohesive implants to go unmentioned. Both Sientra and Natrelle silicone gel implants are cohesive, and often mistakenly called "gummy bear" implants. However, the actual true "gummy bear" implants are the Allergan style 410 "highly cohesive" textured-surface form-stable (teardrop-shaped) implants. These are more firm than the Sientra or Natrelle silicone implants. All are cohesive, but the 410s are "highly cohesive" and are therefore more firm to touch. Just so you know.

Choose the larger Allergan Natrelle implants in the widest width that matches your actual pocket width. If you are really that narrow, then high profile it is! Best wishes! Dr. Tholen

Richard H. Tholen, MD, FACS
Minneapolis Plastic Surgeon
4.9 out of 5 stars 238 reviews

Sientra shaped Hp 425 cc or Natrelle 475 cc style 20?

 Either implant may be reasonable for your breast size and it really comes down to your personal preference.  The Sientra shaped implant will result in less upper pole fullness and therefore a more natural look.  The Natrelle round style 20 will result in more upper fullness (similar to the photo you posted).  Some consider this look less natural, however, many women like the accentuated upper pole.  However, I would not loose sleep over this decision.  You will have a very nice improvement with either implant.  Best wishes, Dr Lepore. 

Vincent D. Lepore, MD
San Jose Plastic Surgeon
4.9 out of 5 stars 49 reviews

Choosing breast implant shape

I agree that both implants will most likely look good for you in the size difference is inconsequential.  In my practice I typically use a moderate profile round implant to achieve a more natural look to the breast.  If you are concerned about the bubble shape in need to ask your surgeon about the risk of this using high profile implants.  Because you're confused I think it is important that you revisit your board certified plastic surgeon and discuss your concerns in detail.

Impalnt choices

Both implants you chose can be reasonable options. 50 cc difference is not that much, just slightly bigger than a shot glass. Shape is probably more important for you.

Steven Wallach, MD
New York Plastic Surgeon
4.1 out of 5 stars 24 reviews

Sientra Breast Implants Shaped Round Base HP vs Natrelle Style 20

Thank you for your question.

Here are two details which may help you make your decision:

  1. The textured shaped implants have a more natural slope on the top half of the breast.  They don't give the augmented "bubble look" up top. If you want to maintain a more natural shape, choose the textured shaped Sientra Breast Implants..
  2. The textured shaped implants are more firm than smooth round gel breast implants. If softness and feel is very important to you, then choose the Style 20 Natrelle.  Sientra and Mentor also make soft smooth round breast implants comparable to the Natrelle Implants. They give great results.
Also, your surgeon is right.  Whichever implant you choose, pick the size that you want.  I agree that you shouldn't compromise the size you want, just to get the textured anatomically shaped gummy bear implants.

The Sientra Shaped Classic Base Implant comes in a 450cc, but the BWD is 13.0 which is wider than your 12.5 cm width measurement.

I hope this helps.

J. Jason Wendel, MD, FACS
Nashville Plastic Surgeon
5.0 out of 5 stars 143 reviews

Breast width remains an important measurement

It is often fairly hard to make an implant decision.  Because of the variety of brands and types the process can get quite confusing.  This is why it will be important for you to prioritize what you are trying to accomplish.  The size of the implant, both volume and width is critical.  If you have a certain size in mind anything bigger or smaller than that will not provide the ideal result for you.  The shaped implants are the best implants for most patients in terms of providing the most natural shape, but some patients actually prefer the look that a high profile or extra high profile implant provides.  If you are thin and going on top of the muscle definitely consider the shaped implant.  Under the muscle with some breast tissue you can likely go with either and so I would guide you toward choosing the ideal size and width of the implant.

All the best,

Dr. Remus Repta

Remus Repta, MD
Scottsdale Plastic Surgeon
4.9 out of 5 stars 153 reviews

Chosing a Sientra Breast Implant Size

This is a great question since it can be very confusing to patients and physicians.  Sientra makes a tremendous breast implant but their sizes can be a little limiting.  Your surgeon is limiting you on width in order to prevent so much side breast and keep the implant centered under your nipple.  I have found however, that going a little wider to get the desired size is not a problem.  I have gone up to 2 cm wider to get a bigger size and that has worked very well.  The advantage the Sientra breast implants have for breast augmentation is that they produce such a natural feeling breast with a very low incidence of capsule contracture and as a result I prefer then to Allergan.I hope that helps.Best regards

Brian Windle, MD
Kirkland Plastic Surgeon
4.9 out of 5 stars 50 reviews

Breast Implants

Determining breast implant size can be very confusing to the patient. There are several different manufacturers and different style of implants. The most important factor in picking an implant are the patients chest and breast measurements. After these dimensions are known, the woman has options as to the type of implant she desires. Each implant has different characteristics. For instance, shaped implants are slightly firmer than the round gel devices. However, the shaped devises are more natural appearing with less fullness in the upper pole. Round gel devices are very close in appearance and each manufacturer has slight changes in the consistency of the gel. A patient can't go wrong with choosing any of the implant manufactures, they are all good.

Robert M. Wald, Jr., MD
Orange County Plastic Surgeon
5.0 out of 5 stars 18 reviews


Go with the highly cohesive. It has a lifetime warranty and a 2 year capsular contracture warranty. If you're going under the muscle, why would you need the shaped implant? Even the round implant under the muscle has a great look.

Donald W. Kress, MD, FACS
Frederick Plastic Surgeon
4.1 out of 5 stars 12 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.