I would discuss your concerns with your plastic surgeon. Without additional information or photos, it is difficult to comment. Your situation does seem a bit unusual though.
You may need an implant exchange with work done on your capsule to shape it with a smaller implant.
As you noted in your question, the implant spreads out to your underarm area. The most important determining factor to picking the right size breast implant is the patient's breast width. The implant that was placed appears to be too wide for your breast width. I would discuss this with your plastic surgeon to determine the appropriate size implant. This may involve changing the shape, projection and size of the implant, all resulting in a more natural appearance.
Your concerns are understandable as there is a significant size difference in the expander and implant volume. My approach is to use a slightly larger implant for the expanded volume. This is because the expander distends and sticks tissues out much more than what is possible for an implant. So it makes sense to go up a notch higher with the implant per se.
You mention about a much larger implant being placed with over distended pocket.
I would certainly speak to your board certified plastic surgeon to address this issue. The skin envelope may have to be modified for a smaller implant and a full discussion needs to be done with all consequences explained in detail.
I do hope you can address all these issues in the near future.
Most often, a particular size breast implant is chosen because it fits securely in the breast pocket. We want the expander pocket to ultimately be slightly smaller than the implant that is chosen.
Explain your concerns to your plastic surgeon. I am sure they will work with you to make you happy.
Thank you for your questions. There can be several reasons why a larger implant may have been needed at the time of surgery. I will frequently place 50 to 100 cc larger implants than my fill volume at the second stage reconstruction. This is a difficult question to answer but should be answered by your plastic surgeon. at this point I would recommend giving yourself some time to heal. If the implants are still too large once you are 3 months out from surgery then a revision with smaller implants may be needed. Best of Luck.
Thank you for your question and I am sorry that your results have not been what you anticipated. Without knowing the full details of your procedure it is difficult to know why the substantial increase in size of implants after tissue expansion and I would recommend voicing your concerns to your surgeon. The two of you can review the operative plan and discuss how it does not match your current results. Your surgeon wants you to be happy and should be able to explain to you the rationale behind 775cc and offer treatment recommendations. Best wishes.