What are the pros and cons of placing silicone implants over or under the muscle?

If you have little fat and less breast tissue, then sub muscular may be better for you because it gives you a more natural appearance. The muscles serve to hide more of the implant, so it won't be so visible or palpable. Mammograms are also easier to perform. Subglandular may be an option if you are a bodybuilder and need to show off your muscles. The cons of sub muscular placement include a bit more discomfort and a bit longer of a recovery period. 

It's a great question. I strongly prefer under the muscle implants because the muscle provides another layer of camouflage for your implants. The muscle contours the top of the implant to give it a more natural slope and hide rippling of the implant. Implants under the muscle have a decreased risk of scar tissue forming around the implant (capsular contracture).  Also, breast cancer screening with mammography gives better images of breast tissue when implants are placed under the muscle. Although an implant on top of the muscle can be a good choice for some women, for very thin women there is not enough camouflage for the implant to look natural. When considering breast augmentation make sure you find a board certified plastic surgeon who will take the time to answer all of your questions and explain all of your options, so that you can decide if breast augmentation is right for you.

Well as you mention your surgeon will pick what is best for you depending on your body, the idea would be to choose which ever way you would have a more natural look and ultimately would be best for you, your Plastic Surgeon will examine you and offer you his recommendation, and explain to you why he thinks one placement or another would be beneficial for you. There is never one option that works for all women. Everyone is different and requires an individual assessment and plan.

When breast enlargement with implants first became popular, the implants were placed just behind the breast on top of the pectoral muscle.  With time, it became obvious that there was a high occurrence of hardening of the implants due to tightening of a scar tissue layer (called a capsule) that always forms around breast implants upon healing.  Despite numerous theories and lots of research, we still don't know the exact cause of this contracture (tightening) of the scar capsule, why it occurs or doesn't in some individuals, or how to completely prevent the problem.  We do know that capsule formation is a normal part of your body's healing around a foreign object.  Over the years, surgeons discovered that placement of the implants behind the pectoral muscle offers significant protection against this scar tissue tightening, so this has become the norm for most surgeons.  Also, for many patients implants placed behind the muscle look more natural because your own breast and fatty tissue camouflage the border of the implants.  So a more natural appearance and softer breasts are considered advantages of submuscular placement.  However, this is a more extensive surgery than placement just behind the breast, with more pain in the first few days post op, and some people may notice a strange "jiggling" or "rippling" of the breast when the pectoral muscle is flexed strongly.  Although this does not occur often, it can be upsetting to some patients, especially body builders.  That is why for some patients who are fitness buffs or body builders, surgeons will discuss the option of placing the implants over the muscles, as long as the patient accepts the increased risk of scar capsule tightening.

It is impossible to give an accurate assessment of what you would be a candidate for without examining you or at least seeing the photos. Generally speaking if you have very little breast tissue or some-but perky-- you might be a good candidate for placement under the muscle. Sometimes if a patient is a candidate for a lift--and the nipples do not point down)- but wants only increase in volume -- then the implants ( preferably -silicone) can be placed over the muscle.Breast implants were universally silicone and were placed over the muscle since the beginning in the 1960s. Under the muscle became popular in the 90s when only saline was used and wrinkling was prominent.Seek an experienced Board Certified Plastic Surgeon for in person consultation.

The advantages of under the muscle include less risk for contracture, more fullness on top, no visible rippling on top, and better mammograms.  The only bad thing is you have muscle distortion when you flex your chest muscles.When on top of the muscle, you don't have the movement and pain may be less.  I always recommend under the muscle unless the patient chooses otherwise.  And if you go above the muscle, I would always suggest the shaped implants.

That would take a multiple page response. Best to seek additional in person discussions with your chosen surgeon. I prefer unders as do the majority of boarded PSs.. 

I prefer to place implants mainly under the muscle especially in patients with  thin soft tissue coverage.

Thank you for the question.

There are pros and cons to the placement of breast implants in 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.   
Best wishes with your upcoming surgery.

The major problem of breast augmentation we, as plastic surgeons, have faced for 50 years, is hardness, or "capsular contracture". This is best understood as being like "shrink wrap". The body reacts to any foreign object by creating a wall, or a capsule, of what is much like scar, around the object, and implants are no exception.When all goes well, that capsule  space is large enough to allow the implant to sit  without any pressure but if the capsule shrinks down around the implant, the shape and feel is distorted. ( This is a little different with "textured implants). It becomes rounder, firmer, and less like a natural breast. Why this happens is not completely clear ( although the science around it is becoming more understood.) What is important to you, as a patient, is that many, many studies show lower risk of contracture regardless of the type of implant  when implants are under the muscle. ( usually "partial sub-muscular, dual plane, or other descriptions". The difference compared to above the muscle is substantial, and becomes greater as the years go by.There are  other reasons. But capsular contracture is such an issue, that after my early years in practice seeing so much of it, I do not feel I can reasonably advise patients to have their implants placed above the muscle. That does't mean it cannot happen with implants under the muscle, because it can and does. But the risk is just so much less.Putting implants above the muscle to try to avoid doing a lift usually means big, saggy breasts. if you need a lift, you need a lift.Weight training and doing exercises involving the pec muscles has not been a good reason to go above the muscle either, although distortion of the breasts when the the muscles are activated can be an issue. Many many patients who are very active are also very lean, have very little body fat and breast tissue, and would not look good with implants under minimal tissue. Too much visibility of the implants, poor shape,etc.It's a long, complex , but important discussion. Those are a few points. Avoidance of contracture remains the single most important factor in the choice, in my view.