Will going from 375cc HP silicone to 550cc silicone give me another cup size?

Thank you for your question.   Generally when patients come to my practice and would like to increase their current size by "a full cup", I tell them then need to go about 150-200cc larger.   You are right in that range, so I think you will end up a cup size larger.   In doing that your surgeon may choose to use a higher profile implant to get you more projection without making your breast wider.   This would be based on your base diameter measurement (width of your breast).   Basically if you are 13cm wide with your current implant, you may need a higher profile to remain 13cm, but give you more projection.   It is important you are seeking a board certified plastic surgeon with breast revision surgery experience.   If you have done this and your surgeon is telling you to not go larger than 550cc, you should listen.  You will always find someone who will go larger if you search enough, but even though you may want to be larger it may not be a good idea for your body.  Good luck to you.

First, I hope you are clear on why your surgeon would not place larger implants in you the first time around. If the surgeon is saying no for your own safety, that is not something to ignore. You can always find a surgeon to say yes, but I strongly urge you to be clear on the risks you are taking on, and if that is worth it to you. In some patients the skin envelope is so tight, there is only so big of an implant you can fit in, and over time the tissue stretches and can accommodate a larger implant. In contrast, some patient's skin and tissues simply do not tolerate a large implant well, and you can have stretching and sagging earlier when placing a large implant in this situation. Generally speaking, going from 375 to 550 would result in an increased cup size, yes, and would also offer greater projection. I cannot say if this will be the case for you in particular without seeing you in person. Also, a larger implant puts greater pressure on the breast tissue and skin, and over time it can actually flatten the native breast tissue you have, meaning you would not have greater projection than you do now. It's unclear from your question how much time has passed since your first surgery. I would advise waiting at least 3 months from your last surgery before having the breast implants revised. 

Thank you for the question.  

Generally speaking, the best online advice I can give to ladies who are considering revisionary breast augmentation surgery 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 "up a cup size” or "DD cup" etc means different things to different people and therefore prove unhelpful.
Also, as you know, cup size varies depending on who makes the bra; therefore, discussing desired cup size may also be inaccurate.
3. Once you feel you have communicated your goals clearly, allow your chosen plastic surgeon to work with you in determining the best plan to achieve your goals.

I hope this, and the attached link (dedicated to revisionary breast augmentation surgery concerns), helps. Best wishes.