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.

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

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.