What is the purpose of placing implants only partially under muscle?

Even when breast implants are placed under the muscle, there is still a portion (the very bottom and the very lateral portion) that is not covered by muscle. This is because the implant is circular and the muscle is triangular. The triangle doesn't cover all areas of the circle.If you want more information regarding breast augmentation you can download my free breast augmentation planner at aBetterBreast.com  This planner is filled with over 30 pages of helpful information in a very easy to read format. It includes internet links to other very helpful resources regarding surgeon qualifications and implants etc.  It really is a must read for anyone considering breast augmentation.Good luck in your search for information regarding breast augmentation.

Thank you for your question.  The placement of the breast implant partially under the muscle and partially under the breast tissue is technically called a "Dual plane" position of the implant (because it is under two different types of tissue).  The pectorals muscle does not cover the very far lateral and inferior aspect of the chest.  Therefore it is impossible to place the implant completely under the muscle.  Technically nearly every sub muscular implant is a "dual plane" augmentation.  Total muscle coverage of the implant is not done for cosmetic surgery as there is more discomfort and the potential for unnecessary complications.  

Placing implants partially below the pectoralis muscle seems to offer the best advantages for the most people. This is called a dual plane position.Risks of capsular contracture are lower, there is more tissue coverage over the implant in the upper portion of the breast ( which can help give a more natural apperance), it preserves more blood supply to the overlying skin and nipple, and allows for a more predictable position of the bottom of the breast ( infra mammary fold) and a more predictable position of the implant.

The purpose of placing implants under the pectoralis muscle is to cover the implant with as much natural tissue as possible, in effect "camouflaging" the implant, decreasing the risk of visible rippling, and in theory giving a more natural result. The problem with covering the ENTIRE implant with the muscle was that implants would often remain too high, producing undesirable results. The "dual plane" technique (where the top part of the implant is under the muscle and the lower part is covered by only breast tissue) has largely corrected the problem of "high-riding" implants, while still offering the advantage of muscle coverage.

Most patients who have breast
augmentations today have breast implants placed in a combination or “dual
plane” position. This approach has the same benefits and disadvantages of a
total “submuscular implant”, but with a lesser tendency to ride high on the
chest wall. The disadvantage as compared to a total “submuscular implant” is a
higher tendency for bottoming out.The ideal placement in any
particular patient depends on their particular anatomy and understanding of the
pros and cons of each approach. Keep in mind, that following the advice
from a surgeon on this or any other website who proposes to tell you what to do
based on two dimensional photos without examining you, physically feeling the
tissue, assessing your desired outcome, taking a full medical history, and
discussing the pros and cons of each operative procedure may not be in your
best interest. I would suggest you find a plastic surgeon certified by the
American Board of Plastic Surgery and ideally a member of the American Society
for Aesthetic Plastic Surgery (ASAPS) that you trust and are comfortable with.
You should discuss your concerns with that surgeon in person. Robert Singer, MD FACS La Jolla, California

The lower level of the breast mound, particularly that of the augmented breast, is located inferior than where the inferior border of the pectorals muscle sits. Thus placing a breast implant completely under the muscle would in most patients leaving it sitting too high. This is a particular issue the larger the breast implant becomes. 

Thank you for the question.Dual plane breast augmentation refers to the technique where breast implants are placed under the muscle superiorly and in the sub glandular position inferiorly. I think this is the best way to go for most patients. On the one hand, patients benefit from the sub muscular position with increased tissue coverage of the breast implant, less chance of encapsulation, less potential for rippling/palpability of the implants and less interference with mammography.On the other hand, because the implants are not completely sub muscular there is the potential for less “distortion” of the breast implants with pectoralis movement. Generally, in my opinion, the breasts also look better with breast implants in this position.I hope this, and the attached link, helps.

Back in the 1980's it was common to try to keep the implant totally under the pectoralis; that is not done anymore as the dual plane where the top is covered by muscle and the bottom and outside are not yields a far more natural appearing result without all the animation deformities.