Is 400cc silicone under the muscle huge for someone who is 5ft and 115 lbs?

I agree with others that an exact measurement of your breast and body characteristics is crucial to determine the size of a breast implant, but, in my opinion, based on your height and weight, the size implant you mention is way too large and can significantly increase your risk of complications. Hope this helps. 

I appreciate your question.

The size of implant best for you is dictated by your
chest wall measurements. Once we determine that we can choose the profile
based on what you want or need to achieve.  If you are seeking a natural look, then the diameter of the implant should be equal to or, more ideally, smaller than the width of your breast. The breast width is a measurement of how wide your breast is at the base, which should be measured at the level of the nipple. Choosing an implant that is smaller in diameter than your breast width will avoid the "side breast" fullness that is often associated with a more artificial appearance. Other than that, you should choose the implant based on volume, not on the dimensions of the implant. You should choose a board certified plastic surgeon that you trust to help guide you in this decision.

Silicone will give you a fullness at the
top (upper pole fullness).

Silicone implants come pre-filled with a
silicone gel and are the softest implant available. They feel more natural,
which makes them a good option for women with less natural breast tissue; but
they require a larger incision. It may be more difficult to realize if this
type of implant has ruptured, so it is important to monitor them with annual
follow-up visits. Additionally, because this implant contains a more liquid
silicone (less cross-linked), if this implant should rupture, it will leak only
into the scar capsule formed around the implant but may cause some discomfort
or implant distortion.

Anatomic gummy bear implants might be a
good choice to give you volume.

These highly-sought-after, anatomic
implants offer a look that more closely resembles the natural silhouette of a
breast, and, therefore, are a very attractive option for individuals seeking a
natural-looking, aesthetic primary breast augmentation. Additionally, these
implants are an especially excellent option for patients undergoing restorative
or corrective breast surgery because they provide more stability, shape, and
reduced incidence of capsular contracture. Compared to other types of silicone
gel implants, the silicone in the cohesive gel implant is more cross-linked;
therefore, should the implant shell “rupture,” it maintains its shape and
silicone does not leak.

During your breast augmentation
consultation, you should feel the different types of implants available, and
try on various implant sizers in front of a mirror to help you to get an idea
of how you will look following the surgery. You should also bring pictures of
the look you would like to achieve, as well as a favorite top to wear when
trying on implant sizers.

The best way to assess and give true
advice would be an in-person exam.

Please see a board-certified plastic
surgeon that specializes in aesthetic and restorative breast surgery.Best of luck!

Dr. Schwartz

Board
Certified Plastic Surgeon

Director-Beverly
Hills Breast and Body Institute

#RealSelf100Surgeon