Breast Implant Position Part III

"Under the Muscle" Breast Implants, a Blog by Dr. Loftus

Placing the implants under the muscle is also called submuscular. Total submuscular coverage is when an implant is completely covered with muscle. It is mostly under the pectoralis major ("pec") and partially under the serratus muscle. The serratus muscle attaches on the side of your chest and connects to your shoulder blade. In the partial submuscular position the implant is only under the pectoralis muscle so the side of the implant is not covered in muscle. Most plastic surgeons use a variation of the partial submuscular technique rather than total submuscular.

The above image shows a grayish white implant under the red pec muscle. The breast tissue is yellow colored. Positioning the implant under the muscle leads to slightly more pain, swelling and a longer recovery. That being said it is still very tolerable. So do not make the decision solely based on this fact.

Breast Shape

When the implant is positioned under the muscle it is not in direct contact with the breast tissue for the most part. Therefore the implant has less impact on shape. Further, the muscle is tighter and has more of an effect on changing (usually flattening) the implant shape than the breast tissue does. Thus the implant has less ability to shape the breast if it is under the muscle and is more affected itself than if it were placed in a subglandular position. When you move your arms you move your pectoral muscles and may further distort the implant. This can result in visible distortion of breast shape. This is not usually visible through clothing. Nonetheless it can be distressing to women.

Another problem with placing the implant completely under the muscle is that it can make the implants sit too high resulting in an unnatural breast shape. The reason for this is that the pectoral muscle attaches to the chest wall above the inframammary fold in most women. The inframammary fold is the crease under your breast that defines the lower border of your breast. If you place the implant under the muscle and it sits above the inframammary fold the volume of the implant is held high in the breast. Also, the tightness of the muscle over the lower portion of the implant often does not allow as much projection and volume as you want in the lower half of the breast. In fact, the total submuscular position is not frequently used because of the degree to which the implant is distorted. In partial submuscular coverage many surgeons will partially disconnect the pectoralis fibers above the inframammary fold, leaving the fibers along the breast bone intact. This allows the muscle to function while letting the implant sit at the inframammary fold. Tension on the implant is relieved, improving shape. A submuscular implant still will not provide as much projection in the lower pole as a subglandular positioned implant.

Advantages of Submuscular Breast Implants

One huge advantage of placing implants under the muscle is getting more tissues to cover the implant. This is important for women who do not have much breast tissue (i.e. most women seeking breast augmentation). With extra tissue over the implant you are less likely to see rippling and will feel the implant less. More advantages are less risk of developing capsular contracture and less interference with mammography.

At this point, you may feel confused because there are some advantages and disadvantages to placing the implant over or under the muscle. You may feel like neither one of these options works just right for you. Wouldn’t it be great if we could give you the advantages of both? Well, maybe we can… Read "Part IV: Over and Under the Muscle!"