If you’ve spent any time online lately, you may have seen the internet buzzing after Kylie Jenner answered a fan’s question about her breast implants. Her response was surprisingly specific:
“Half under the muscle, 445 cc moderate profile silicone.”
Almost immediately, plastic surgeons across the country began hearing requests for “dual plane” breast augmentations in the 400 cc range. But what do Kylie’s comments actually mean when it comes to breast implant placement—and should implants go over or under the muscle? To fully answer this question, we need to cover some relevant history.
How Breast Implant Placement Has Evolved
Silicone implants have been around awhile—since the 1960s. There have been six generations of silicone breast implants that have evolved over the years. For over a decade spanning 1992 to 2006, we weren’t even allowed to use them for cosmetic breast augmentation (except in breast cancer patients, interestingly. We were always able to use them for breast reconstruction).
The reason for the ban was to conduct further safety studies into whether silicone implants could be causing autoimmune disorders such as rheumatoid arthritis. The conclusion of these studies was that there were no epidemiological findings to confirm this, and silicone implants returned to the market for cosmetic use.
The alternative during that time was saline implants—that is, a silicone shell filled with saline as opposed to a silicone shell filled with silicone. Most plastic surgeons prefer silicone because of its more natural feel and appearance.
The place we actually put the implant—and the incision used to get there—has also ebbed and flowed over time, influenced by rates of capsular contracture, implant visibility, and societal trends.
In the early days, implants were frequently placed just under the breast gland using an incision in the crease where the breast meets the body (the inframammary fold) or along the border of the areola.
This technique was plagued with a complication called capsular contracture—a pathologic thickening and tightening of the scar tissue that naturally forms around all breast implants. We believe this occurs due to the low-grade, subclinical presence of bacteria around the implant—not enough to cause an overt infection, but enough to create inflammation that leads to thickening of the capsule.
This thickening can lead to deformity and, in some cases, pain. The remedy is more surgery, and if more surgery fails, the implant has to come out and unfortunately stay out.
Why Surgeons Started Placing Implants Under the Muscle
The response to this complication was to experiment with different implant locations—namely, under the pectoralis muscle—as well as different implant textures, smooth versus textured surfaces, and new insertion techniques.
These changes included insertion sleeves to prevent the implant from touching the skin during placement and antibacterial washes to irrigate both the implant and the breast pocket.
While we did see lower rates of capsular contracture with these changes, we also saw ramifications of placing breast implants under the muscle. These included animation deformity (the implants move in a sometimes dramatic way when the patient flexes her pectoralis muscle) and lateral or inferior displacement of the implant over time.
When you think about it, placing an implant beneath the muscle is a highly unnatural, non-anatomic location. Nature did not intend for there to be a foreign object under the pectoralis muscle.
What Is a Dual Plane Breast Augmentation?
At least a partial solution to some of the shortcomings of having the implant totally under the muscle was to place it partially under the muscle, as Kylie’s implants were.
This is called a dual plane breast augmentation. The upper part of the implant benefits from muscle coverage, while the lower portion sits beneath the breast tissue.
With this technique, we can still see animation deformity, implant malposition over time, and discomfort. However, it can also create a very natural-looking upper pole.
For patients with a wide sternum and for patients with certain anatomic variations such as tuberous breast deformity, it can sometimes be more effective to achieve better cleavage with breast implants over the muscle.
Textured implants, which were also associated with lower rates of capsular contracture, eventually turned out to be associated with a rare form of lymphoma called Breast Implant-Associated Anaplastic Large Cell Lymphoma (BIA-ALCL).
Alas, there is no perfect solution.
The Rise of Subfascial Breast Augmentation
Or is there?
The Motiva implant came on the scene about 15 years ago globally and was FDA-approved in the United States in 2024.
This implant boasts a lower capsular contracture rate than competitors (presumably due to its unique surface, which is thought to be more biocompatible than traditional smooth implants while avoiding the ALCL concerns associated with macro-textured implants). It also claims a lower rupture rate.
As a result, a newer trend has emerged: subfascial breast augmentation.
In this technique, the implant is placed beneath the fascia of the breast gland—which separates the implant space from the ductal tissue that harbors bacteria—but above the pectoralis muscle.
Subfascial breast augmentation is often combined with an absorbable mesh placed along the lower portion of the implant to act as an internal sling (sometimes referred to as an internal “bra”). It may also be combined with fat transfer to camouflage implant borders and disguise rippling, which is the visibility of implant surface undulations through the skin in thinner patients.
Is this the perfect modern solution?
Not so fast.
Breast Implant Placement and Breast Cancer Screening
There are other considerations, including the impact of implant placement on breast cancer surveillance.
All implants, regardless of location, cause some degree of obscuring of breast tissue on routine mammograms. Placing implants above the muscle has a greater impact on mammography than placing them below the muscle.
That said, we do not see an onslaught of women with breast implants—whether above or below the muscle—presenting with missed breast cancers.
Part of this may be that implants push outward on breast tissue and actually make cancers more palpable. Part of this may be the overall lower rate of breast cancer observed in women with implants in general, potentially due to inflammatory mechanisms that are ultimately protective.
That said, I usually recommend adding a contrast-enhanced breast MRI to the screening regimen in addition to yearly mammography.
245 cc round demi Motiva implants above the muscle showing a natural appearing upper pole
Should Breast Implants Go Over or Under the Muscle?
In particularly thin patients, and with increasingly large implants (445 cc is on the larger end of the spectrum), it can be difficult to create a natural-looking upper pole.
My personal aesthetic preference is a gentle, natural slope away from the chest wall as opposed to an abrupt takeoff. Less round implants that assume a more teardrop position when standing, along with fat transfer, can help achieve this look.
The truth is that there is no universally “best” breast implant placement. Whether implants are placed above the muscle, below the muscle, or in a dual-plane position depends on a patient’s anatomy, aesthetic goals, activity level, family history of breast cancer, and long-term priorities. Implant placement is a nuanced topic that deserves a full discussion during any breast augmentation consultation.
I consider a patient’s activity level, aesthetic goals, anatomy, and family history of breast cancer when counseling patients. My bias tends to be toward breast implants over the muscle in many patients because they can look just as good as a dual-plane augmentation without the discomfort, prolonged recovery, and animation deformity.
Was it “wrong” to place Kylie’s implants partially under the muscle? No, of course not. Like many things in life—and plastic surgery is no exception—there is rarely one “right” technical way to do things. But having a thorough and thoughtful discussion during a breast augmentation consultation is always the best way to go.
