Surgery to increase breast size involves inserting silicone sacks (implants) filled with silicone gel or salt water (saline) under the chest muscle and skin. The procedure involves making a cut (incision) in the armpit, under the breast or around the areola (the dark area around the nipple) from where the implant is inserted.
https://healthpoint.co.nz/private/plastic-surgery/ormiston-hospital-plastic-surgery/