What does overfilling breast implants mean?

Saline implants are filled by the surgeon during the operation (silicone implants come sealed form the manufacturer, and size is not adjustable by the surgeon).  IN order to make sure the implants ripple less and have better shape, the manufacturers give the surgeons an acceptable range within which a saline implant functions safely.  Most surgeons will fill the implant to the top of range, to reduce crinkles and rippling.  This is called overfilling.   I do NOT recommend filling the implant BEYOND the top of the suggested range of implants.Best wishes,RM

Overfilling implants refers to saline implants and this is performed to reduce the rippling that some see with implants. The trade-off is a firmer implant.

Thank you for the question.  Saline (NOT silicone gel) breast implants can be overfilled far beyond the upper limits of manufacturer's recommendations. Sometimes, in appropriate cases, this may be what is necessary to achieve a patient's goals. Sometimes, in addition, the adjustment of the breast implant capsules is necessary also. You will find many examples of such cases (larger breast augmentation surgery outcomes) on the attached link. Best wishes.

You can think of a saline implant as a balloon. The manufacturer recommends an overfill of about 20cc but they have been shown to be able to be filled much more than that. They do start loosing their shape and can significantly distort the appearance of your breasts. 
 I do overfill espcially since the FDA has restricted saline and silicone implants to a maximum saline shell size of 800cc and maximum silicone size of 800cc. I do not know why that number was picked arbitrarily. 
So, I do do breast reconstructions greater than that with XL tissue expanders which do pride a greater diameter and projection and upper pole fullness and allow the size to be adjusted either up or down. Also, the shell of the saline implants are very thin and can dreflate more easily. You may want to visit my site below which explains everything, esp for XL sizes which is my specialty, either initially or revisional surgery.