Implants under or over the muscle?

I am 5'4 and weigh 48 kg (105 pound). I have very little body fat which means my rib cage and collar bones show. What type of implant surgery is most suitable for me, "unders" or "overs"? Thank you!

Doctor Answers 11

Implants under or over muscle?

Sarah I always put implants on top of the muscle regardless of how thin you are and I'll give you my reasoning why. I hope I can explain my reasoning so as you will be able to have a good understanding, and at least then judge for yourself.  However you will hear many differing opinions on this, and every plastic surgeon does things in a subtly different way that makes their surgery work for them and their patient.

The two main reasons implants were put under the muscle many years ago were: firstly to disguise them, and secondly to reduce capsule formation. I'll talk about capsule first. Capsule is the body's reaction to the implant.  Everybody gets a capsule to an extent, as all implants are "walled off" from the surrounding tissues. This "wall" around the implant is the capsule.  Normally you wouldn't even know it was there, as it's very thin and flimsy, like cling film.  However if the capsule gets "thick" or "tight" it squeezes the implant which then adopts a firmer, rounder shape. The implant can then be felt, and even seen. We know now how to reduce the incidence of this thick capsule. There are several techniques we use to help prevent it, so capsule is now nowhere near as common as it once was. Great news. But putting the implants under the muscle is not one of these techniques and does nothing to prevent capsule (the same goes for texturing or different shapes).

Now let's talk about putting implants under the muscle.  It was thought that with more "cover" over the implants  (i.e. skin plus breast PLUS muscle), the edge of the implant above would be less visible.  However even in a very thin woman with small breasts, an appropriately sized implant on top of the muscle will look just as good, with minimal if any visibility of the upper pole of the implant.  This is true with any implant, including round ones.  If a thick or tight capsule forms this changes, and the implants become visible or palpable, whether under or over the muscle! It doesn't matter.

So the first thing is to ask the surgeon what steps he or she takes to prevent capsule. That is the most important thing in breast implant surgery. Get them to show you typical results at two or three years, not just a few months (when all implants look good because capsule hasn't had time to develop).

Putting implants under the muscle has other problems.  Firstly the operation is painful, as opposed to on top which has minimal pain.  Secondly the implants move when the muscles move.  Thirdly a band can develop across the breast after a year or so.  This band is the detached muscle pulling on the breast tissue and distorting it. Finally if a problematic capsule does develop, the capsule itself cannot be removed entirely (at least not easily), because the capsule is attached to the ribs which are under the muscle.

Now many implants put under the muscle look fine if the above problems don't occur. But they do occur occasionally.  However these problems are less of an issue if implants are placed on top of the muscle.

What I can say is that this work very well for my patients.  I follow nearly all of them for five years if I can.

All the best.


Geelong Plastic Surgeon
5.0 out of 5 stars 30 reviews

Placement Of Implant For Petite Or Thin Patients

Placement Of Implant For Petite Or Thin Patients

Sub-muscular is still the most common placement, especially with low body fat. I am not sure why you would consider different placement.

Jed H. Horowitz, MD, FACS
Orange County Plastic Surgeon
5.0 out of 5 stars 96 reviews

What is best for you may not be best for someone else...

so you really should invest in a consultation so your surgeon can review the pros and cons with you and allow you to make the best decision you can for yourself.  I personally believe implants under the muscle are better and have my reasons but you have to accept the muscle distortion that will occur.  But in your situation, going above the muscle would make me think more about the anatomic gel implants due to your thinness.  But best to see someone in person who can help you appreciate the differences more.

Curtis Wong, MD
Redding Plastic Surgeon
4.8 out of 5 stars 32 reviews

Above or below the muscle

There are pros and cons to the placement of breast implants and the “sub muscular” position versus the "sub glandular position”. I will try to outline some of the differences here; you may find the attached link helpful as well.
I think it is in the best interests of most patients seeking breast augmentation surgery to have implants placed in the “dual plane” or sub muscular position. This positioning allows for more complete coverage of the breast implants leading to generally more natural feel/look of the implants in the long-term. This position will also decrease the potential for rippling and/or palpability of the implants (which may increase with time, weight loss, and/or post-pregnancy changes).
The submuscular positioning also tends to interfere with mammography less so than breast implants in the sub glandular position. The incidence of breast implant encapsulation (capsular contraction) is also decreased with implants placed in the sub muscular position.
On the other hand, sub glandular breast implant positioning does not have the potential downside of “animation deformity” ( movement/ distortion of the breast implants seen with flexion of the pectoralis major muscle) they can be seen with breast implants placed in these sub muscular position. Also, the immediate recovery period may be more comfortable after sub glandular breast augmentation as compared to sub muscular breast augmentation surgery.
The goal of breast surgery is to achieve beautiful breasts. Beauty is determined by several factors including symmetry, skin tone, position of breast on the chest wall, position of areola, cleavage and volume. 

Implants under or over the muscle?

Hello Sarah
Thank you for your question.
There are advantages and disadvantages both ways, and there are numerous factors that, when considered together, will help you and your Plastic Surgeon to jointly arrive at a decision. This kind of decision, can only, in my opinion, be arrived at, in consultation with your Plastic Surgeon. Even with the best of intentions, no online forum can properly address the contributing factors, and you cannot arrive at this decision without the expertise and guidance of your Plastic Surgeon.
It is vital to speak with your Surgeon. Communication is the essence, so that you can both, jointly, and in agreement, make the correct choice for you.
After so many years in practice, I am still astounded that no two patients are ever the same, or ever present with exactly the same contributing factors.
I wish you well in your journey.

Implants under or over the muscle?

There are two choices for breast implant placement: sub-glandular (under the breast tissue and in front of the chest muscle – the pectoralis muscle) or sub-muscular (under or partially under the chest muscle). The best location depends on many factors including: tissue thickness, weight, desired outcome, and individual anatomy. Each position has advantages and disadvantages:

Subglandular implant benefits:
  • A shorter recovery time.
  • Less discomfort initially.
  • No distortion of the breast when the pectoralis muscle flexes.
  • Mild preoperative sagging can be improved, especially if no breast lifting procedure is performed.
  • Easier surgical procedure.
  • Larger implants can be placed.
Subglandular implant disadvantages:
  • The implant may be more visible.
  • More visible rippling, especially in patients with a small amount of natural breast tissue.
  • Generally, saline implants do not produce a good result in front of the muscle.
  • Higher incidence of capsular contraction.
  • “Bottoming out” in some patients.
  • Some radiologists have more problems reading a mammogram with an implant in front of the muscle.
Submuscular implant benefits:
  • Usually results in a better appearance for naturally small breasted women
  • Less tendency for seeing ripples of the implant.
  • A more natural feel to the breast especially in slender women who don’t have much of their own breast tissue.
  • Less interference with mammograms, although most radiologists take additional views no matter where the implants are placed.
  • Lower rate of capsular contraction.
  • Less of a chance of “bottoming out” where the implant bulges at the lower aspect of the breast and the nipple and areolas tend to appear excessively elevated.
Submuscular implant disadvantages:
  • Recovery usually takes a little longer and is more uncomfortable initially.
  • There may be an “animation deformity”, which is a temporary distortion of the breasts when the pectoralis muscle is flexed. Body builders and weight lifters generally prefer implants in front of the muscle.
  • It is harder to achieve cleavage in women who have widely spaced breasts.
  • The implants often ride higher on the chest.
Actually, 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. Both saline and silicone gel implants can produce a good cosmetic result in the appropriate patient. Most patients prefer the feel of the silicone gel implant.

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

Robert Singer, MD
La Jolla Plastic Surgeon
4.6 out of 5 stars 19 reviews

Implants under or over the muscle?

I think it is in the best interests of most patients seeking breast augmentation surgery to have implants placed in the “dual plane” or sub muscular position. This includes athletic patients.
The submuscular positioning allows for more complete coverage of the breast implants leading to generally more natural feel/look  of the implants in the long-term. This position will also decrease the potential for rippling and/or palpability  of the implants (which may increase with time, weight loss, and/or post-pregnancy changes).

The submuscular positioning  also tends to interfere with mammography less so than breast implants in the sub glandular position. The incidence of breast implant encapsulation (capsular  contraction)  is also decreased with implants placed in the sub muscular position.

On the other hand, sub glandular breast implant positioning does not have the potential downside of “animation deformity” (movement/ distortion of the breast implants  seen with flexion of the  pectoralis major muscle)  that can be seen with breast implants placed in the sub muscular position. 

Overall,  after considering pros/cons carefully, I find that there are  many advantages to placement of breast implants in the sub muscular ( dual plane) position. I hope this, and the attached link, helps.

Breast implants placed under the muscle usually best for thin woman with little breast tissue

Thank you for your question.  Generally speaking placing the breast implant beneath the chest muscle provides significant additional coverage for the breast implant and has many other advantages.  In very thin people with prominent rib cage is an little breast tissue this extra coverage can improve the result and avoid visibility of the breast implant.

However you need an in person examination and consultation by a board certified plastic surgeon.  If your breasts are sagging or have any shape abnormality, a lift or other revision may be necessary to allow placement under the muscle.  However if your breasts are normally shaped and nipple position is normal sub-muscular placement should be possible.

Implant location

Your best bet is to start with a consult by a board certified plastic surgeon. In addition to your height and weight, your surgeon will need to perform a thorough examination of your breasts to assess how much breast tissue and drooping of the breasts is present before making this decision. Typically, very lean women with minimal sagging of the skin benefit from the implant being placed behind the muscle. Again, a consult in-person will be necessary to best answer your question.

Renee Burke, MD
Barrington Plastic Surgeon
4.7 out of 5 stars 24 reviews

Implant position

The ideal postion for implant placement depends on a number of factors, some of which include shape of breast , amount existing  breast tissue, degree of Ptosis(droop), level of physical activity etc..
It is difficult to give you an answer without formally examining you however from what you have described in your question under the muscle is probably going to be your best option. 

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.