Going from 390cc saline to 375cc silicone? Will there be to much extra sagging? Or should I go 405cc.

There will not be much sagging because the difference between the two sizes is minimal. The implant selection should be based on a combination of your desired size, soft tissue dynamics, breast base diameter and skin elasticity.  I recommend an in-office examination as well as a detailed discussion with a surgeon who you are comfortable with.   Finally, make sure your surgeon is a Double-Board Certified Plastic Surgeon certified by the American Board of Plastic Surgery (ABPS), a member of the American Society of Plastic Surgery (ASPS) and the American Society of Aesthetic Plastic Surgery (ASAPS).Best,Dr. DesaiBeverly Hills Institute for Aesthetic Plastic SurgeryHarvard Educated, Beverly Hills & Miami Beach Trained, Double-Board Certified Plastic Surgeon

Thank you for your question. This question would best be served after an exam of your current results and a discussion of the exact dimensions of the implants in question. Saline implants tend to widen the surrounding capsule over time so if the initial implant was 12 cm, the capsule is now likely more like 13-14 cm wide. If you a placing a new silicone implant, you need to choose an appropriately sized implant that maximizes the width of your breast, but at the same time, if you do not increase in cc's, then it will likely lack projection and may result in some sagging of the skin. So your surgeons concerns are valid. If however, you want to keep the same size, then you might be well served with considering a small lift (mastopexy) either at the time of the exchange or in a delayed fashion. Discuss this option with your board certified plastic surgeon.Best of luck!

Your 390 cc saline implant also has a shell which should be added to your total volume.   Effectively, your 390 cc implant is actually around a 415 cc implant.   Silicone implants are listed as a total volume including silicone and shell.   You won't feel or look any larger with your 405 cc implant so I would recommend following your plastic surgeons recommendation.  

and gel implants do have a reputation for being 'softer' in look even at the same size.  So go with the 405 and don't look back.  You should not be any larger than what you appreciate you are right now.  Now if you wanted to be smaller, then going down some would be warranted.

That really is totally up to your surgeon. In the operating room they can try each size and see which works better. I usually have the patient pay for a lift or skin excision if I think it is needed and if you do not need it I give the money back. Better to have paid and not need it then need it and not paid. Communicate with your surgeon on this one and have a plan.DrRickAZ

Valid concern 
Remember that a saline implant is roughly 10 percent larger than the same size silicone implant .
So a 390 saline is equivalent to a
420 cc silicone assuming similar base diameters .

Would need to see you breast to determine how much sag you will have with smaller implant volume 

Good Luck 
Dr Shamoun 
Newport Beach California 
ABu Dhabi UAE 

Going up a few ccs will not change your look and will allow you to keep pretty much the look you have. BTW we always use high profile silicone if replacing saline with silicone as the saline tend to have a higher profile and patients that change a moderate profile saline for an equal size moderate silicone implant almost always feel they are smaller based on loss of projection.