550cc or 650cc? (Photo)

Thank you for the question. Despite your good description of measurements, online consultants will not be able to provide you with specific enough advice to be truly helpful. Ultimately, careful communication of your goals (in my practice I prefer the use of goal pictures, direct examination/communication in front of a full-length mirror, in bra sizers, and computer imaging) will be critical.
Generally speaking, the best online advice I can give to ladies who are considering breast augmentation surgery ( regarding breast implant size/profile selection) is:
1. Concentrate on choosing your plastic surgeon carefully. Concentrate on appropriate training, certification, and the ability of the plastic surgeon to achieve the results you are looking for. Ask to see lots of examples of his/her work.
2. Have a full discussion and communication regarding your desired goals with your plastic surgeon. This communication will be critical in determining breast implant size/type/profile will most likely help achieve your goals.
In my practice, the use of photographs of “goal” pictures (and breasts that are too big or too small) is very helpful. I have found that the use of words such as “natural” or "C or D cup” etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on him who makes the bra; therefore, discussing desired cup size may also be inaccurate. Again, the use of computer imaging has been very helpful during the communication process, in our practice.
3. Once you feel you have communicated your goals clearly, allow your plastic surgeon to use his/her years of experience/judgment to choose the breast implant size/profile that will best meet your goals. Again, in my practice, this decision is usually made during surgery, after the use of temporary intraoperative sizers.
I hope this (and the attached link, dedicated to breast augmentation surgery concerns) helps. Best wishes.

Thank you for your questions.  Plastic surgeons have general guidelines that are typically followed to aid us in implant choice for our patients which include the patients original breast size and shape, breast base width, and patient's desired outcome/size.  There are different methods that surgeons use in their office to help the patient communicate their goals on postoperative size as well as show the patient what they may look like with a certain size implant.  Those methods include computer software that generates a 3D rendering or an sizing system used during the consultation.  There are many implant options available that allow us to customize a patient's outcome.  For example, there are multiple implants with the same width each with different volumes and projections.  I recommend returning to your surgeons to discuss why a certain implant was chosen for you.  Make certain that you are going to a surgeon board certified by the American Board of Plastic Surgery.

Implants of different volumes can have different shapes and the choice is based upon your overall anatomy.

I think you need to go back to the board certified plastic surgeon you are planning on having your procedure with and go over the implant selection process and why he/she selected the implant they did for you. Your anatomical measurement will help to determine the best choices of implants for you. First and foremost you need to be comfortable with your surgeon and trust his/her opinions in getting you the result you are looking for.