The four placements — subglandular, submuscular, dual plane, and subfascial — really come down to which layer of your chest the implant sits behind, and whether the muscle gets released. Each has trade-offs.
When you start researching breast augmentation, you quickly run into a wall of jargon. "Half under the muscle, half over the muscle" — what does that even mean? And what about subfascial? Let's break down the four most common implant placements in plain English.
Every implant placement involves three main layers of your chest:
The implant goes somewhere in this stack. The differences are about which layer it sits behind.
"Sub" = under, "glandular" = breast gland. So this means under the breast tissue, but on top of the muscle.
Picture it from the side:
The muscle is left completely alone — no detachment, no release.
"Sub" = under, "muscular" = muscle. The implant sits under the entire pectoralis muscle, which covers the implant from top to bottom.
From the side:
The muscle is the front "blanket" of the implant. This is the most heavily covered placement.
This is what most plastic surgeons (myself included) used as our default for the last 15 or so years.
The implant is:
To make this work, we disconnect a portion of the muscle from where it attaches at the rib cage — and sometimes a little along the sternum as well. That release allows the lower half of the implant to drop into a more natural position while the top half still has muscle coverage.
The cost of releasing the muscle is muscle flex / animation deformity — that weird movement you sometimes see where the breast distorts when the patient flexes their chest. The more muscle you release, the more risk you run of this. Too aggressive a release is where you really start to see it.
This is why a lot of patients are opting to have their implants moved from under to over the muscle — it eliminates animation deformity. There's also a way to tell which placement you currently have if you're not sure.
"Sub" = under, "fascial" = the fascia, the thin coating on top of the muscle.
Subfascial is essentially a relative of subglandular with one important addition. Instead of putting the implant directly under the breast tissue, we lift the fascia (the top coating of the muscle) off the muscle and put the implant between the fascia and the muscle.
From the side:
So your muscle stays down — there's no animation deformity — but the fascia goes up and provides an extra layer of coverage on top of the implant.
The thinking behind subfascial is:
For patients interested in muscle-sparing techniques that still offer some biological coverage on top of the implant, subfascial is a really nice middle-ground option. (For a detailed look at one of those techniques, here's a writeup on Preservé vs. traditional over-the-muscle augmentation.)
| Placement | Implant Location | Muscle Released? | Animation Risk |
|---|---|---|---|
| Subglandular | Under breast tissue, on top of muscle | No | None |
| Subfascial | Under fascia, on top of muscle | No | None |
| Dual plane | Half under muscle, half over | Partial | Mild–moderate |
| Submuscular | Fully under muscle | Yes (more) | Higher |
There's no universal "best" — every placement has trade-offs. The right choice depends on:
The four main implant placements — subglandular, submuscular, dual plane, and subfascial — are essentially a discussion about which layer of your chest the implant sits behind, and whether the muscle gets released.
If you're consulting for an augmentation or considering a revision, ask which placement your surgeon recommends and why — the reasoning matters as much as the placement itself.