Your dilemma is a freequent one!
The good news is that 25cc's really is too small an amount to make the difference between "just right" and "too big."
The implants do look about 10% smaller when they are behind the muscle as compared to how they look when trying them on in a bra. So if you liked the look of the 350cc in a bra, the 375cc is a good choice, and plenty of volume to move you into the full C cup range.
Good luck with your surgery!
Let's look at the numbers
The only way to determine what is right for you is to perform a dimensional breast evaluation. First, determine the appropriate implant width. The implant should be situated, so that the central area of the implant is directly under the nipple. The radius of the implant will then demonstrate the adequate amount of cleavage. Add your preexisting breast tissue and skin volume to decide the amount of cleavage.
Once you have decided on the appropriate radius for the implant, double it to decide the diameter. Use a range of about 1 centimeter to decide implant volume. For instance, if you like the implant radius to be 6.5 centimeters, then your implant diameter should be from 12.5 to 13.5 centimeters. Next, pick the projection of the implant:
Low - softer more natural- especially desirable for patients with pointy or conical breasts.
Moderate - a middle range for those that want a little more oomph, but want to still look natural.
High Profile - for that very sexy projecting breast.
For example, if you like a 13.3 CM width you can get:
Low profile- 360cc- 13.4cm w x 3.7 cm projection;
Mod profile- 421cc- 13.3cm w x 4.3 cm projection;
High profile- 500cc- 13.0cm w x 5.2 cm projection.
For you, I am not sure what we are comparing, but most likely if they are in the same category, there is very little difference between the two.
I think you will be a "D"
Cup size is a fashion statement....and many people wear the wrong size bra. You have to have some faith in your surgeon with regard to size.
Having said that, by the height and weight you stated, I think you will certainly be in the full C range and maybe in the D range, depending on the bra manufacturer. There are many other factors that would have to be taken into consideration, which would require an exam before I could say much else.
Let your surgeon help you.
Once you see your surgeon for the pre-op consultation, he/she will be able to help you decide which implant size is best for you. Also, know that the saline implants have a range of fill so that a "350" implant can be filled to 380 cc's or a little more. A "375" implant can be filled to 400 cc's, etc. This gives your surgeon some flexibility during the procedure to give you the best possble result. Also, realize that a difference of 25 cc's is less than 2 tablespoons of saline and therfore fairly minimal.
If you are still concerned about it not being the perfect amount after surgery, ask you surgeon about post-operatively adjustable implants.
The Volume Difference is too Small to Agonize over
The volume you are talking about , especially in a moderat plus profile will make almost no difference visually so go with th 400 cc for psychological reasons.
Choosing breast implant size
Breast implant size is a very important issue to be discusssed with your plastic surgeon prior to surgery. There are various measurements that your surgeon should take to help guide the decision making process. The ultimate volume/size that you can become has more to do with your skin elasticity and soft tissues than your actual preference. Meaning, that although you may want to become a "D" cup for example, if your skin only can accommodate a "C" cup, then that will be your final size.
Patients can try on various sized implants in bras prior to surgery to get a general idea of how they may look. I prefer a more accurate method which uses 3D computerized imaging to show the patient what they may look like with a specific implant placed and imaged on their actual torso. This is very helpful for the patient in simulating their final outcome and takes alot of the guesswork out of which implant to choose. I have been using this for about six months now with great results.
Choosing breast implant size - 400 cc
The difference in size between 400 and 375 cc is not significant and I would highly doubt that this difference is clinically observable. I would not risk the higher size if you are still unsure. Remember, this experience should be fun and exciting, not stress-inducing. You will be happy either way.
Saline implant size advice
Many women fret over 25 or 50cc differences in implant size. The fact is, the difference is very small. 375cc though is a large implant. I consider implants that are 400cc or larger as "oversized" implants.
When choosing an implant, the most important features are the diameter and the projection. For diameter, you want implants that are the same size or narrower than your breast width. Choosing the correct diameter helps prevent the common complaint of the implant "sitting under your arm." Projection depends on the volume desired and the ability of your breast to handle that volume. For most women, moderate or moderate plus implants work best. Higher profile implants are more common when replacing missing breast tissue, such as in reconstruction.
I advise on trying to stay natural. If you want to "play up" the look of your breasts, a pushup bra will do wonders (particularly with implants).
Not much difference between 375 and 400 cc breast implants
It is not true that implants under the muscle look smaller, at least in the long run. Most women wish they had gone a bit larger if asked a year or so after the operation. If 375 was placed on one side and 400 on the other, you'd have to look very critically to see the difference. Probably 400 cc will be your choice but I would reconsider silicone gel implants. My patients much prefer them.
Sizing of implants prior to surgery
It may be a good idea for you to bring in pictures of the look you would like to achieve to show your plastic surgeon. This may help him get an idea of what natural cleavage and volume you want while also not going too small or too big. Remember that internally your anatomy is very different, a difference of 25cc will not effect the results of the size. I would not worry too much. Definately emphasize that you do not woatn a fake look and make sure your plastic surgeon understands your wants and needs. For more information, please check out before and after photos of patients. Good luck!