The standard procedure used to increase the volume of a breast is still by means of an implant. A breast implant is a silicone envelope filled with either a cohesive silicone gel (which cannot leak should the envelope rupture or tear) or salt water (saline solution). The two basic implant shapes are ‘round’ and ‘teardrop’ (or anatomical shaped) , both of which come in a variety of dimensions and volumes. The implants are placed behind the mammary glands or behind the chest muscles through a small incision in the (future) fold under the breast, via an incision to the lower edge of the areola, or via a small incision in the armpit. Breast asymmetry can sometimes be corrected by inserting two different implants .