Is There a Big Difference Between 360-390 Implants and 390-420?

Is There a Big Difference Between 360-390 Implants and 390-420? In my opinion, no there is only a 30 cc (2 tablespoon difference)
 

The difference in volume is only about 30 cc and should not really impact your decision.  It may be slightly wider implant with a mm or two of increased projection.

When considering upsizing breast implants I always want patients to make sure that the risks outweigh the benefits.  Each time you have surgery there are small risks of infection, implants settling in the wrong position, scarring etc that we routinely undertake.  The vast majority of times this is a non issue. But we always say in plastic surgery that "the enemy of good is perfect."  Meaning that if we take something good and try to make it perfect there is a risk of causing a bigger problem.

Thus, upsizing one implant will likely make such a small change that it isn't worth the risk/costs.  A push-up bra could easily solve your problem.  However, if you are very unhappy with the size and are looking for 2-3 size larger implants then I'd consider moving forward.  One size up is very difficult to perceive much of a change.

Best of luck.

Vincent Marin, MD

La Jolla Plastic Surgeon

There is not a lot of difference between the implants at all.  The main thing is that the larger implant will have a slightly larger diameter by a few mm, and perhaps a slightly greater projection (go to the site and look at implant specifications).  Personally/professionally, going up one size without a good reason, doesn't seem worth it.

If you are looking for more projection, look into high profile implants.  For a 30" chest wall, your implants may give you too much fullness, especially laterally, the cleavage area, and even the upper pole.

The short answer is no. An Allergan medium profile style 68 390 cc implant is .3 cm wider and no difference in forward projection by measurement. 

In general, if the implant was sized properly relative to the breast width the first time, you can go up to a Moderate Plus Mentor or a high profile Allergan and add to the forward projection size by up to a half cup size. If the tissues have had a chance to soften and settle around the original implant and the capsule space is reasonable, you can change to and implant that is 1 to 1 1/2 cm wider and increase the breast size by about a half cup size at the base. The maximum is the do both an increase of the width and the profile. 

In changing to a 390 (filled to 420) cc implant from a 360 cc implant I doubt that you would feel it was worth the cost but it's not difficult to do if you already have an inframammary crease incision and the tissues have adjusted to the first implant.