Breast augmentation involves placing an implantable medical device (a breast implant) behind the breast (known as "subglandular" placement) and/or chest muscle (known as "submuscular" or "subpectoral" placement. Breast augmentation can increase the volume of the breast in naturally small breasted women, can replace volume that was lost after breastfeeding or major weight loss, change the breast shape (such as in tubular breasts), and create better symmetry to the breasts if they are naturally different sizes or shapes.
All breast implants have a shell made out of an inert polymer called silicone. The shell surface can be either smooth or textured. Smooth walled implants roll around subtly in their breast pocket, mimicking the movement of a natural breast, while textured implants encourage soft tissue ingrowth into their small surface interstices, keeping the implant more stiffly in place.
Breast implants have a variety of base widths, projection amounts and fill volumes. There is not a "one size fits all" approach to breast augmentation. The best implant for each breast will be carefully selected and matched to the space to achieve the specific goals for that particular patient.
Silicone gel is an inert polymer with no known human allergies, sensitivities or reactions. Like a gummy bear candy, the molecules are stuck to one another in a cohesive matrix. Silicone is more viscous than saline. In contrast to saline, it flows differently within its shell and can often create a more natural look and feel to the breast, like breast tissue. Women must be 22 years of age or older to be offered silicone gel implants for breast augmentation, as per the FDA's regulations.
Saline-filled implants are available to all women for breast augmentation over the age of 18. A silicone shell is inserted into the body and then filled to its desired volume by a board-certified plastic surgeon with saline fluid. Saline has the consistency of water. Underneath very thin skin, folds of a saline implant might be seen or felt more often – this is known as implant "rippling" or "wrinkling."
Some saline implants have the advantage of being postoperatively adjustable via a remote injection port – this is commonly used in some types of breast reconstruction procedures to fine-tune the final implant volume over months before the implant port is removed.
Silicone gel implants were first created in the late 1960s and have undergone several different generations with ongoing technological improvements. Saline filled implants were created as an alternative to silicone fill and became popular in the 1990s and early 2000s. Over the last 20 years, significant advances have been made to silicone gel implants. In fact, we are now implanting the 7th and 8th generation of silicone breast implants. The newest silicone implants have a slightly higher fill (96% fill versus the previous generation's 85% fill) and more cross- linking of the silicone molecules, increasing the stiffness or "cohesiveness" of breast implants.
"Baffling" refers to an internal channel structure within the implant, like layers on a shelf. Theoretically, these channels allow the saline inside to flow in different directions within the outer implant to simulate the feel of a silicone implant, with purported decreased incidence of rippling and sloshy liquid movement.
Different degrees of stiffness or "cohesiveness" (cross-linking of the silicone molecules) are now available in silicone gel breast implants. The most "liquid" ones are softest and flow most easily, and are most commonly used for routine breast augmentation. The most highly cohesive silicone implants are stiffest and tend to hold their shape most firmly, with potential advantages for post-mastectomy breast reconstruction. An intermediate stiffness implant is also available, which can be beneficial for breast augmentation patients who wishes to have silicone but have experienced rippling with the less cohesive devices.
Did You Know: Silicone gel breast implants are the most widely studied medical device in the history of medical devices? Historically, silicone gel implants received negative media attention and were sensationalized in the 1980s and 1990s, with apparent claims of adverse associated health problems, prompting removal and replacement of older silicone implants with saline filled devices. Since that time, extensive FDA-directed prospective clinical research with long-term follow-up has confirmed no association between silicone gel implants and any chronic autoimmune disease. Read information from the ASPS about the safety of breast implants and the potential association of textured implants with an extremely rare and treatable condition called BIA-ALCL.
For more information about breast augmentation, breast implant science and safety, visit a board-certified plastic surgeon who is an ASPS member. Be sure to #DoYourHomework before having any cosmetic plastic surgery procedure!
Dr. Karen Horton is a board-certified plastic surgeon in San Francisco and an ASPS member surgeon: www.drkarenhorton.com