Breast augmentation involves placing an implant beneath the existing breast tissue to enhance size and shape. Determining the precise anatomical location is a major decision during planning. The placement choice significantly influences the surgical approach, recovery period, aesthetic outcome, and long-term health monitoring. This decision is individualized, based on a patient’s anatomy, implant type, and aesthetic goals.
Defining Implant Placement: Submuscular vs. Subglandular
Implants can be placed in one of two primary planes relative to the chest wall. Submuscular placement positions the implant partially or completely beneath the pectoralis major muscle. This technique is often referred to as “dual-plane” when the implant sits partly under the muscle in the upper section and partly under the glandular tissue in the lower section.
Subglandular placement positions the implant directly behind the mammary gland tissue but in front of the pectoralis major muscle. In this approach, the implant rests on top of the chest muscle, separated by the fascia. It is sometimes called “over the muscle” placement to distinguish it from the submuscular option. These two locations represent the main choices for implant positioning.
Rationale for Submuscular Positioning
Submuscular placement is frequently chosen to provide an additional layer of tissue coverage over the implant. This coverage helps camouflage the implant, making the edges or folds less visible or palpable, particularly in individuals with minimal natural breast tissue. The muscle tissue creates a smoother, more gradual slope in the upper breast, contributing to a natural-looking contour.
This positioning is also associated with a lower risk of developing capsular contracture, a complication where the internal scar tissue surrounding the implant tightens. Studies suggest that placing the implant behind the muscle may lower the incidence of this hardening compared to subglandular placement. Muscle support is thought to stabilize the implant long-term, potentially reducing the risk of displacement or sagging.
Rationale for Subglandular Positioning
A benefit of subglandular placement is that it generally results in a shorter and less painful recovery period. Because the pectoralis muscle is not manipulated or stretched, the surgical procedure is less complex and involves less muscle trauma. Patients often experience less post-operative discomfort and can return to normal activities sooner compared to the submuscular approach.
Subglandular placement also avoids “animation deformity.” This occurs with submuscular placement when the pectoralis muscle contracts, causing the implant to momentarily shift or distort the breast shape during upper body movements. Placing the implant over the muscle eliminates this aesthetic concern for active women or those who engage in strength training. This position may also be preferred for patients who already have sufficient natural breast tissue to provide adequate coverage.
Impact of Placement on Medical Screening
The position of the implant has specific implications for long-term breast health monitoring, particularly mammography. The implant, whether silicone or saline, is opaque to X-rays and can obscure the underlying breast tissue, making visualization challenging. Radiologists must take special images, known as implant displacement views, to push the implant back and maximize the visible breast tissue.
Submuscular placement generally interferes less with mammography than subglandular placement. When the implant is situated behind the muscle, the breast tissue can be more easily compressed and separated from the implant during imaging. Regardless of placement, additional imaging modalities such as breast ultrasound or Magnetic Resonance Imaging (MRI) are often utilized for comprehensive screening and to evaluate the implant itself.