FAQs: Breast Implants – Under vs. Over Implant Placement – Breast Augmentation

Under vs. Over Placement of Breast Implants- Which is best?

Few questions seem to create more confusion or controversy among both patients and surgeons than whether the implant should be placed above the muscle or below the muscle. The first problem is that there is no best answer for any one person. Each person’s own physical characteristics may make the choice for one woman or her surgeon entirely different than the choice for another. Another problem is apparent confusion about the medical terminology that applies to this issue.

For a full explanation of breast implant placement with anatomical illustrations, click here.

Subglandular – this means placement of the implant above the pectoral muscles but below the mammary gland. Technically, all implants are subglandular because implants placed below muscle are also below the mammary gland. However, this term refers to placement just below the mammary glands and above the muscle. This placement is also referred to as retroglandular or submammary.

Subpectoral – often loosely referred to as “submuscular,” subpectoral means placement of the implant below the pectoralis major muscle. In subpectoral placement, the implant is only partially submuscular due to the nature of the pectoral muscle under which the implant is placed. The lower half of the implant is not covered by muscle in this type of placement. This placement is also referred to as retropectoral.

Submuscular – although many refer to subpectoral placement as “submuscular,” fully submuscular placement actually means placing the implant under not only the pectoralis major muscle (covering the upper portion of the implant) but also under related muscles at the lower half of the implant.

Subfascial - Another option instead of over OR under the muscle is called “subfascial” has recently been reported (pronounced like "fashion" without the "n"), which is a sort of compromise between the 2. Although it is thin, the faschia is usually substantial enough to provide a layer behind the breast and in front of the implant. See illustrations of this placement by visiting the profile of Richard A. Baxter, M.D.

Advantages and Disadvantages

Capsular contracture - Many surgeons believe, based upon clinical studies regarding placement of the implant and contracture rates, that placing the implant below the pectoralis muscle (subpectoral) or fully submuscular, reduces the rate of capsular contracture (review separate FAQ on contracture) when compared to above the muscle placement of the implant. Keep in mind that there is not total agreement as to whether this is truly the case. One alternative that has been suggested to prevent capsular contracture is the textured implant which, even if placed above the muscle, is also supposed to reduce the rate of capsular contracture. Whether this is true is also the subject of some debate. Furthermore, many believe that textured implants are more likely to create visible rippling. Surgeons who disagree with this view of textured implants claim that rippling is a result of improper filling of the implant and not at all with the surface of the implants. Read more in the “textured vs. smooth” FAQ.

Rippling – In women with little breast tissue, subpectoral or fully submuscular placement is likely to reduce the chances of visible rippling of the implant. This should be true regardless of the originating reason for the rippling (underfilling or textured surface, depending on the opinion held) because the implant is partially or fully covered by muscle, in addition to breast tissue.

Mammography – Although technology increasingly makes better breast imaging possible with and without implants, placement of the implant below the muscle is thought generally to improve mammography by making it less likely that the implant will prevent proper imaging of all of the breast tissue. Subglandular (or above muscle) placement, on the other hand, is thought to be more likely to interfere with imaging. While implants containing alternative fills such as soy or peanut oil have been experimented with due to their being radiolucent (they allow imaging to pass through the implant), none have been approved for use so the above muscle placement of the implant still causes some concern with regard to mammography.

Sagging – in most fully submuscular placements and potentially in subpectoral placement as well, many surgeons contend that the implant is better supported than in subglandular (above muscle) placement, resulting in less sagging of the augmented breast in the long term.

Appearance

Initially, and especially with silicone implants, implants were predominantly placed above the muscle (subglandular). Most surgeons can agree that in the ideal case where a woman has adequate breast tissue to disguise the implant and assuming no rippling or contracture, above the muscle placement would result in the most likely natural looking result because the implant is behind only the tissue itself, the tissue that is being augmented and which will take on the augmented shape. In women with adequate or a lot of breast tissue, subglandular (above muscle) placement is likely to yield the most natural looking result. Women who work out with weights complain of an unusual appearance while working out with implants that are behind the muscle as the muscle can contract the implant into a distorted shape. In most women with average to little breast tissue, under the muscle placement can help to avoid the “fake” look of implants that are apparent because they are closer to the surface.

A potentially more natural look for over the muscle placement is mostly true in women with any significant sag or droop (ptosis) of the breast tissue. Because the pectoralis muscle tends not to sag, placement of the implant behind the muscle means that the implant is likely in these women to be higher on the chest than sagging breast tissue, which will tend to look like separate tissue hanging from the firmer, higher mound of the implant. Because of this, in cases where subpectoral or submuscular placement is desired (read on for the reasons this might be so), many surgeons will recommend a mastopexy (breast lift) in conjunction with a subpectoral or submuscular augmentation when there is significant droop.

Due most of the factors listed above, most surgeons prefer under the muscle placement, whether subpectoral or fully submuscular, but again, the patient’s physical characteristics will affect the decision as well as the surgeon’s preference.