Breast Implant Placement

Implant Placement: Over or Under the Muscle?

breast implant positionTake a moment to look at a diagram to see the size and location of the muscles that make up your chest wall.

Notice that the pectoralis major muscle is a large fan-shaped muscle. You will see that it does not cover the lower, outer aspect of the chest wall.

Most surgeons detach the muscle from its lower origin along the ribs when placing the implant under it. This means that only about half the implant is covered by the muscle. The bigger the implant, the less of it that is covered.

The pectoralis minor muscle is much smaller and lies under the outer edge of the pectoralis major. The serratus muscle lies along the sides of your chest wall. The main sensory nerves to your breast come up between the slips of this muscle to enter the back of your breast tissue and from there to the rest of your breast. Most surgeons place the implants on top of the pectoralis minor and serratus muscles, but below the pectoralis major muscles.

Over the Muscle (Subglandular) Breast Implant Placement:

  • Pros: When textured implants are used, the capsular contracture rate is only 5–10%. In women with a moderate amount of breast tissue (a B cup or larger), this can be an excellent choice and produce very natural-looking breasts that age well. The recovery is usually easier than when the implants are placed in a submuscular position. End results are usually achieved in a matter of weeks.
  • Cons: The use of smooth implants in a subglandular position very frequently (up to 70%) results in capsular contracture. When textured implants are used in thinner women with small breasts rippling may be visible in the upper and inner aspects of the breasts. It is also easier to see the upper edges of the implants when they are placed over the muscle.

Under the Muscle (Subpectoral) Breast Implant Placement:

  • Pros: Using smooth implants under the pectoralis muscles reduces the capsular contracture rate to less than 10%. In thinner women, the added bulk of the muscle over the upper and inner aspects of the implants makes the edges less visible and the curve of the breast more natural. When textured implants are used, the rippling in the areas under the muscle is usually invisible.
  • Cons: The recovery is more uncomfortable for several days. It takes longer for the swelling to subside and for the breasts to settle. You may need several months to see the end results. When the pectoralis muscle is contracted during exercise or in some daily movements, the muscle flattens the implants and pushes them outward, changing the shape of the breast. Occasionally, an indentation over the implant is seen along the edge of the muscle. When there is a moderate amount of breast tissue that is lax or becomes lax in time, it may sag below the position of the implant that is held in place by the muscle, resulting in a double bubble deformity.

Read more of Dr. Saltz’s articles about breast augmentation: