How much bigger is my 234 cc under muscle silicone breast implant than 176cc?

The 58 cc difference is slightly less volume than 2 shot glasses - so not a huge difference. See your plastic surgeon for best advice. 

When implants sit at different levels is not really a function of size. Are they above or below the mucle? was the muscle fully released, is there a capsule,scarring,infection etc?

The scientific answer is that your larger implant is about 2 ounces larger than your smaller implant. As for why they are sitting in different positions, that question requires a discussion with your surgeon. It may be that one breast required a release of a constriction which can tend to cause the implant on that side to settle more slowly. It may also be a sign of something not being right. Best to let your surgeon know so that you can rest comfortably knowing what is happening.Best,Dr. Pyle

and using one company's catalog, a 170 cc implant is 10.5 cm wide and the 235 cc implant is 11.8 cm wide  with the projection 2.6 and 2.9 cm respectively... the difference is quite small and barely noticeable. 

To respond in exact #s 58 ccs difference. Not very much in amounts or volume. If thinking of going larger increase at least 100 ccs......

Your implant volume went up about about 30% as for sitting high on the chest is this because the surgery was just performed?  If so, give it a few months.

Thank you for the question but it is difficult to answer in an objective fashion. If you have concerns about breast asymmetry after breast augmentation surgery, best to discuss these directly with your plastic surgeon. He/she will have the benefit of in person examination.  Breast asymmetry  after breast augmentastion surgery may be related to a variety of factors,  other than differences in the sizes of breast implants utilized. Pre-existing breast asymmetry, chest wall asymmetry, differential breast implant “settling”, breast implant displacement/malposition problems, swelling asymmetry…are all factors that may or may not be involved. Again, your plastic surgeon will always be your best resource when it comes to good information, advice, and/or reassurance. Best wishes.

Your implants are very close in size and the difference that you see should be minimal.  It is more likely that the problem you're seeing is a difference in implant position.  Please see her plastic surgeon to inquire if the higher larger implant needs to be released surgically to drop into a similar position to the opposite side.