What size implant would give upper pole fullness? 125lbs, 5’4”, wide shoulders and naturally wide breast. (Photos)

The best cosmetic result in any particular breast augmentation patient depends on a variety of factors, including: Your individual anatomy, desired outcome, realistic expectations, a thorough discussion with the plastic surgeon about the options, and an understanding of the pros and cons of any particular implant choice. Proper sizing is not just about the number of cc’s. or the type of implant. The thickness of your tissue, breast dimensions which include the width, height, and projection, as well as chest wall width all need to be considered when choosing an implant. Trying on implant “sizers” of various shapes and volumes while wearing a tight t-shirt, bra, or bathing suit at a preoperative visit will help you and your surgeon choose the optimal implant.

Keep in mind that following the advice from a surgeon on this or any other website who proposes to tell you what to do without examining you, physically feeling the tissue, assessing your desired outcome, taking a full medical history, and discussing the pros and cons of each operative procedure would not be in your best interest. I would suggest that your plastic surgeon be certified by the American Board of Plastic Surgery and ideally a member of the American Society for Aesthetic Plastic Surgery (ASAPS) that you trust and are comfortable with. You should discuss your concerns with that surgeon in person.

Robert Singer, MD FACS

La Jolla, California

Patients often think in terms of cup size when considering augmentation. Unfortunately, devices are sized in terms of milliliters (cc) of volume. This can lead to some confusion when sizing. Additionally, it is important to remember that cup size itself is not standardized with variations from one manufacturer to another. Unfortunately, as many women can attest their cup size in an industry leader such as VS is not necessarily transferable to another brand.
Another point which is often under appreciated is that of anatomy and starting point. Any implant will add volume to the volume which is already present. The implant is additive. A particular volume will not necessarily confer the same cup size to different patients (often times it will not even confer the same cup size to different breasts in the same individual...remember they are "sisters" not "twins"). 
A general rule of thumb is that 125cc can represent somewhere between 1/2 to a full cup size increase. Smaller volume differentials (25-50cc) are typically less consequential representing a volume change of less than a shot glass. However, I have found these numbers, at least anecdotally, to be of little help. Patients often present with notions/goals which do not correlate with these sorts of sterile volumetric assessments.
When sizing patients, there are a number of useful tools including:
-3D imaging (has the added benefit of offering a volumetric analysis of the pre-operative breast)
-Breast sizers (rice bags)
-Goal photos
I also recommend that patients commit to a particular look rather than a cup size. Once a patient settles on a look that pleases them the overall cup size increase becomes less relevant.The key to obtaining a natural result is to stay within the parameters defined by your BWD. This will ensure that you avoid the dreaded "fake" look. With regards to your specific question, the upper pole cannot be preferentially filled out without augmentation of the whole breast. More fullness will affect overall size. The best advice is to start with your BWD and work from there.
As always, discuss your concerns with a board certified plastic surgeon (ABPS).