Is It Possible to Have 600-700cc and Natural Sagging For My Frame? (photo)

If you want to be big, 600-700 cc's will do it and then some.  You may be happy initially, but over time, you can look forward to lots of sagging, back pain, and difficulty getting a bra that is comfortable.  I think it is too large and eventually you will be wondering what in the world you were thinking. Then you will need a lift with smaller implants. I say don't do it.

using larger implants to achieve desired size

The model clearly has very large breasts.   there are a number of problems with large implants. But if this is where you want to be then you will need more than 600 cc to get enough of a change

 

You told us you have 450cc implants, but not their profile. Your too-wide cleavage (too-narrow implants) suggests you have moderate plus or even high profile implants, which are positioned correctly beneath your nipple/areola complexes (NACs), but because of their inadequate size and base diameter, do not give you the look you want.

Thus, large(r) implants are indeed necessary, as well as proper profile choice (widest possible for the volume chosen to fit your pocket diameter) to give you better cleavage while maintaining proper position beneath your NACs. Don't worry one bit about sag; gravity is one of those things that is present 24/7, always exerting its force on your breasts and their supproting structures.

"Beach balls" would be caused by capsular contracture, or simply "forcing" implants that are physically too large for the largest appropriate pocket that can be safely created within your body's anatomy. Violating anatomy causes symmastia and other malposition issues, but large size alone is not absolutely impossible. I frequently place 500-800cc implants in appropriate patients who request them, and whose anatomy allows them. But then again, I do well over 100 breast augmentations yearly, in addition to augmentation plus lifts, lifts alone, transgender breast surgeries, breast reductions, and breast reconstructions/revisions.

BTW, the 30 year old Czech nude model you show in your goal photograph does not have implants, so this is (literally) an unrealistic expectation. That being said, it looks as if your anatomy will support large implants so long as your (experienced) ABPS-certified plastic surgeon knows your goal, does not try to violate physics and anatomic limitations, and is comfortable with using large implants. I think you can have a splendid result, and would NOT recommend switching to a submammary plane (increased risk of capsular contracture, implant visibility, or palpability). For an example of one of my patients who requested 800cc implants (also a professional model) click on the web reference link below--you have to click on the far right photograph (not the arrow) and then scroll down for the final 800cc result. Best wishes! Dr. Tholen