Under the Muscle vs. Over the Muscle

Implants can be placed in one of two positions: between the breast and the pectoralis muscle, or between the pectoralis muscle and ribs. Either way, they are centered under the breast.

Terminology for Implant Position

Other Names for Subglandular Other Names for Subpectoral
Under the breast Submuscular
Over the muscle Under the muscle
Above the muscle Below the muscle
Between the breast and muscle Between the muscle and ribs

Above the Muscle (Subglandular)

Position of the implant above the pectoralis muscle is known as subglandular placement and offers several advantages. This operation involves less discomfort and faster recovery because the pectoralis muscle itself is not disturbed. Your breasts will immediately appear attractive because swelling is minimal. In athletic muscular women it causes less movement (distortion) of the breast when flexing the pectoralis muscle. Women with ample breast tissue might be more likely to select subglandular placement than women with very modest breasts as larger breasts offer more of a cushion between the implant and the skin, thereby not needing the additional padding conferred by the muscle. Read our breast blog video about implants above the muscle.

Breast implant Location

Disadvantages of subglandular position include a higher risk of capsular contracture and greater interference with mammography than subpectoral. Women with thin skin, low body fat, or petite breasts are very likely to feel the implants through the skin and are more likely to have rippling and wrinkling. Large implants are more likely to displace downward, and the risks of nipple numbness and infection are slightly higher.

Below the Muscle

Implant position under the muscle, also known as submuscular or subpectoral placement, offers the advantages of a lower rate of capsular contracture, less interference with mammography, lower rate of rippling, and less likelihood of downward displacement. Thin women with petite breasts may obtain their best cosmetic result with the implant placed under the muscle, which provides more padding between the implant and the skin.

Disadvantages include greater postoperative pain, greater swelling, and a longer recovery period. Swelling can be profound and may persist for weeks or months. During this time, the upper portion of the breast appears unnaturally full. And after swelling subsides, flexing the pectoralis muscles, such as during exercise, may cause the breasts to move and appear distorted while exercising.

Most women are not deterred by these disadvantages as most of the disadvantages are temporary. As for distortion during exercise, most women find this is a relatively minor disadvantage. Hence, most women (even very athletic women) choose implant placement below the muscle, with the exception of body builders (see below). Read our breast blog about placing implants under the muscle.

The “Complete” Submuscular Controversy

Some plastic surgeons tout “complete” submuscular placement, as opposed to subpectoral placement, in which only the upper inner half of the implant is covered by muscle. They claim that the advantage is that the implant is completely covered by muscle, thereby conferring more cushion between the implant and skin along the lower and outer sides of the breast where the pectoralis muscle does not provide coverage. To achieve “complete” submuscular placement, they usually separate the upper portion of the rectus muscle and the anterior portion of the serratus muscle from the ribs. Plastic surgeons who challenge that complete submuscular placement is possible point out that although it is possible to recruit the rectus muscle to cover the lower part of the implant and the serratus muscle to cover the lateral part of the implant, it is not possible to join these muscles together over the implant in most women without distorting the lower half of the breast. Hence, they argue that it is not possible to achieve “complete” submuscular coverage.

Dr. Loftus has found that it is seldom helpful (but very painful) to recruit the serratus muscle for lateral coverage. Whether the rectus muscle can be recruited for coverage of the lower half of the breast is somewhat dependent upon the woman’s anatomy, the size implant selected, and how high or low the implant is optimally placed for aesthetics.

Body Builders

Body builders tend to be thin and muscular. As thin women benefit from implant placement under the muscle, and as muscular women have greater muscular distortion with implants placed under the muscle, body builders found themselves in a quandary when only saline implants were available. Now that silicone is an option, body builders usually choose silicone implants over the muscle. Being silicone, they have a lower rate of rippling, even in thin women. Being over the muscle, there is less distortion with flexion of the pectoralis muscles. Prior to the availability of silicone, these women often had disappointing cosmetic results.