High Profile Vs. Moderate Plus Saline Breast Implants

in very thin patients, I am not a fan of the shape of the HP implants. Therefore, I will advise filling the MP+ to the upper ranges to take advantage of the rippling diminishing tendencies without the overprojected round look

In that case perhaps the moderate plus in an implant with high cohesivity like Sientra (if available) or the Allergan Inspira silicone implants which has less chance for rippling. If you are set on saline implants then I would strongly urge you to consider the IDEAL implant, a recently FDA approved  and now available saline implant made to feel like silicone with a better shape than even most silicone implants. See the below link for more information. 

There are several different schools of thought on this, but the method I use along with many others is to first have the patient select the size (volume) they want by trying samples on in a bra. Wew then determine what implant size is needed to create this same look, since they typically would look a bit smaller implanted than when externally in a bra. Once we know that, we then find which implant at that size has the correct base diameter, which is how you avoid the unnatural separation in the middle and other problems. If it looks like it will be one of the versions of higher profile, we make sure you understand that it will have a rounder (less natural) look. Silicone is often a better choice for thinner women.

To size you up for implants takes a physical exam and discussion of your goals. Everyone carries the volume a bit differently and the bras do not always correlate to the volume.  the moderate plus are a bit wider on a sme vovlume comparison to the hps.
 

I agree with Dr. Rand that breast implants are sized by the width of the breast wherever that is and do not make the breasts further apart or closer together. I would also agree that even properly sized, properly positioned (below the pectoralis muscle), and properly filled, they will still feel ripply on the outer side of the breast and underneath where the muscle doesn't cover (in thin coverage patients). 

The main point that I'd like to make, though, is that high profile saline-filled breast implants are not the same in Mentor and Allergan. Allergan has low, medium, and high profile saline-filled breast implants that are scaled to the width such that a low profile implant gains about a cup size, a medium gains about a cup and 1/2, and a high profile gains about two cup sizes. The Mentor medium profile is essentially equivalent to the Allergan medium profile and their Moderate Plus profile is halfway between the Mentor or Allergan medium profile and the Allergan high profile, but the Mentor high profile saline-filled implant is not scaled for the width and if the same width dimension is used (as it should be) then the volume of the Mentor high profile implant will be much larger than a half cup increase as with the Allergan medium to high profile implant. 

I have no commercial interest in this. It's just the mechanics of dimensions and volume. If a medium profile implant doesn't have enough forward volume for you then (in saline but not gel) choose the Mentor Moderate Plus as the next step up. If you want a high profile saline-filled implant then choose the Allergan/Natrelle one properly scaled to your breast width. 

How to pick breast implant sizes and shapes.

Answer by George J. Beraka, MD
Manhattan Plastic Surgeon
1) This is the most common type of question on RealSelf.

2) It is the surgeon's job to pick the right breast implants, not the patient's. Implant selection is really pretty technical.

3) Make sure your surgeon REALLY understands the look you want. Mentioning a cup size is not enough. Show your surgeon pictures of breasts you like.

4) Then your surgeon has to tell you if your chosen look is realistic for your anatomy. The most common mistake is to go too big.

5) I recommend that the surgeon NOT make a final implant choice in advance, because this is just an educated guess.

6) The surgeon should have a large inventory of different size and shape implants available in the operating room.

7) Then the surgeon can put sterile disposable implant SIZERS in your breasts during surgery, to see what a particular implant really looks like inside you. This is how to make the best choice. A sizer costs only $45, and takes all the guess work out.

8) Finally, the sizer is discarded, and the correct breast implants (based on what you want and on your anatomy) are opened from the operating roon inventory, and put in your breasts to complete the operation.
 

Several points here.  First, "too far apart" comes from the wrong base width of the implant, not whether they are HP or Mod plus.  Second, in a thin girl, saline will for sure be wrinkly and ripply laterally even under the muscle.  The HP salines look bigger and rounder than HP gels at least in Mentor implants so be sure that the HP "look" you like is from saline vs gel.