Subglandular breast implants sit between the breast tissue and the chest muscle, rather than underneath the muscle. This placement has distinct advantages and trade-offs compared to submuscular positioning, and the choice between the two has been debated in plastic surgery for decades. The short version is that subglandular placement offers a more natural-looking contour in certain patients and avoids some muscle-related complications, but it comes with a meaningfully higher risk of capsular contracture and can complicate mammographic screening.
What Subglandular Placement Actually Means
In a subglandular augmentation, the surgeon creates a pocket above the pectoralis major muscle but beneath the breast’s glandular tissue. The implant rests directly against the underside of the breast. In submuscular (or “subpectoral”) placement, by contrast, the implant goes partially or fully beneath the chest muscle, adding an extra layer of tissue between the implant and the skin.
The practical difference is straightforward: with subglandular placement, only your natural breast tissue covers the implant. With submuscular placement, the muscle provides additional coverage. That extra layer matters for everything from how the implant feels to how it shows up on a mammogram. One early comparison of the two approaches found no significant differences in operative blood loss or surgery time, so the decision has always been driven by outcomes rather than surgical logistics.1PubMed. Breast augmentation: a review of subglandular and submuscular implantation
The Capsular Contracture Problem
Capsular contracture is the most discussed risk associated with subglandular placement. Every implant triggers the body to form a thin scar capsule around it, which is normal. Problems start when that capsule tightens, squeezing the implant, making the breast feel hard, and sometimes causing pain or visible distortion.
Two large-scale analyses have found that subglandular positioning roughly doubles the risk. A meta-analysis published in Annals of Plastic Surgery reported that subglandular implants carried more than a two-fold increased risk of capsular contraction compared to submuscular implants.2Annals of Plastic Surgery. The Impact of Breast Implant Location on the Risk of Capsular Contraction A separate risk-factor analysis of Natrelle 410 form-stable silicone implants found an even stronger association: subglandular placement was the single strongest risk factor for capsular contracture in the primary augmentation group, with a nearly threefold adjusted risk ratio.3PubMed Central. Risk Factor Analysis for Capsular Contracture, Malposition, and Late Seroma in Subjects Receiving Natrelle 410 Form-Stable Silicone Breast Implants
The reason for this elevated risk is not entirely settled, but researchers have pointed to bacterial biofilms as a likely contributor. Microorganisms can colonize the surface of implants, forming thin films that provoke a chronic low-grade inflammatory response. This inflammation appears to accelerate capsule formation and tightening.4PubMed Central. The Relationship of Bacterial Biofilms and Capsular Contracture in Breast Implants Because subglandular implants lack the muscle barrier that submuscular implants have, bacteria from the breast ducts or skin may have easier access to the implant surface.
Why Some Surgeons Still Prefer Subglandular Placement
Given the capsular contracture numbers, you might wonder why anyone would choose subglandular placement at all. The answer lies in a problem unique to submuscular implants: animation deformity. When an implant sits beneath the pectoralis muscle, the muscle can contract and visibly push, squeeze, or distort the implant. This happens during exercise, lifting, or even casual arm movements. The result can be an unnatural rippling or jumping of the breast that bothers many patients.
A retrospective review of subcutaneous (pectoralis-sparing) implant placement in breast reconstruction found that none of the patients developed animation deformity, compared to the well-documented rates seen with submuscular approaches.5PubMed Central. Avoiding Breast Animation Deformity with Pectoralis-Sparing Subcutaneous Direct-to-Implant Breast Reconstruction One surgeon’s longitudinal observations confirmed this pattern: subglandular augmentations showed capsular contracture and rippling issues, while subpectoral augmentations showed muscle-induced problems like malposition, distortion, asymmetry, and contour deformity.6PubMed. Results of subglandular versus subpectoral augmentation over time: one surgeon’s observations Each plane has its own set of trade-offs, and the “better” option depends heavily on what the patient wants to avoid.
For physically active patients or those who use their chest muscles intensively, the animation deformity issue can be significant enough to tip the balance toward subglandular placement. A bodybuilder or someone doing heavy bench pressing, for example, may find a submuscular implant visually distracting and functionally uncomfortable during training.
Who Has Enough Tissue for Subglandular Placement
The classic screening tool for subglandular candidacy is the upper pole pinch test. The surgeon pinches the tissue at the top of the breast, and if the fold measures more than about 2 centimeters, subglandular placement is considered feasible because there is enough native tissue to camouflage the implant edges. Patients with thin tissue are generally steered toward submuscular placement, where the muscle provides the additional coverage that their breast tissue cannot.
However, some researchers have questioned whether this test tells the whole story. A review of long-term subglandular outcomes argued that even when the upper pole pinch test is favorable, it only predicts short-term results. Over time, the implant’s pressure on the lower pole of the breast can lead to a distinct set of deformities: thinning of the skin over the lower breast, visible wrinkling, and enlargement of the nipple-areola complex.7PubMed Central. Subpectoral Implant Repositioning With Partial Capsule Preservation: Treating the Long-Term Complications of Subglandular Breast Augmentation The tissue that passes the pinch test at the time of surgery may thin out over years under the weight and pressure of the implant, eventually producing visible edges or rippling that were not present early on.8Aesthetic Surgery Journal Open Forum. Subpectoral Implant Repositioning With Partial Capsule Preservation: Treating the Long-Term Complications of Subglandular Breast Augmentation
This is one of the more honest admissions in the literature: a patient can look excellent after subglandular augmentation for several years and then gradually develop problems that a submuscular placement would have prevented. It suggests that the decision should factor in not just current tissue thickness, but body composition trends, implant size, and realistic expectations about how the breast will change over time.
How Subglandular Implants Affect Mammograms
Breast implants of any type can obscure parts of the breast on a mammogram, but the effect is more pronounced with subglandular placement. When the implant sits directly behind the breast tissue rather than behind the muscle, it blocks more of the glandular area that a radiologist needs to evaluate. A literature review on breast cancer screening in augmented patients noted that subglandular implants present a particular mechanical barrier to mammographic sensitivity, which can delay the detection of tumors.9PubMed Central. The impact of breast cancer on cosmetic breast augmentation outcomes and screening challenges in patients with implants: a literature review
The standard workaround is a technique called the Eklund displacement view, where the technologist manually pushes the implant back against the chest wall and pulls the breast tissue forward before compressing it. A study examining mammographic image quality confirmed that implant placement and whether the Eklund technique was used both significantly influenced how much breast anatomy was visible on the resulting images.10PubMed Central. Study of breast implants mammography examinations for identification of suitable image quality criteria For anyone with subglandular implants, making sure the imaging facility routinely performs Eklund views is a practical step worth verifying before each screening.
Supplementary imaging with ultrasound or MRI can also help fill in the gaps mammography misses. This is especially relevant for patients at higher breast cancer risk. The takeaway is not that subglandular implants make screening impossible, but that they require more effort and awareness to ensure nothing is missed.
Breastfeeding With Subglandular Implants
One question that matters to many patients considering augmentation is whether they will be able to breastfeed afterward. A large study tracking lactation outcomes in more than 3,500 women after primary augmentation found that breastfeeding rates were slightly lower with subglandular placement compared to submuscular. For silicone implants, about 75% of mothers with subglandular placement breastfed their infants, compared to roughly 81% with partial submuscular and 79% with complete submuscular placement.11Aesthetic Surgery Journal. Lactation Outcomes in More Than 3500 Women Following Primary Augmentation: 5-Year Data From the Breast Implant Follow-Up Study
The rate of insufficient milk production followed a similar pattern: about 25% of women with subglandular placement reported not producing enough milk, compared to roughly 18–20% with submuscular placement. The researchers suggested that the implant sitting directly against the glandular tissue may exert more pressure on the milk-producing structures. While the differences are not dramatic, they are consistent enough to be worth discussing with any patient who plans or might consider future pregnancies.
Long-Term Tissue Changes
Breast tissue is not static. An implant exerts pressure on the surrounding tissue, and over time that pressure can lead to measurable thinning of the breast’s glandular volume. A study that tracked patients for twelve months after implant insertion found an average glandular volume reduction of roughly 13% in both breasts, with the degree of reduction correlating with the measured pressure levels.12PubMed. Relation Between Post-Augmentation Parenchymal Atrophy and Local Tissue Pressure The researchers described the relationship between the implant and the surrounding breast tissue as dynamic: the implant can contribute to local atrophy, changes in blood supply, and reductions in glandular volume over time.13Aesthetic Surgery Journal. Relation Between Post-Augmentation Parenchymal Atrophy and Local Tissue Pressure
This matters more for subglandular implants than for submuscular ones, because the tissue between the implant and the skin is all you have. When it thins, the implant becomes more visible and palpable. With submuscular placement, the muscle provides a buffer that helps mask any loss of glandular tissue. The degree of atrophy also has implications for implant revision or removal later: a patient who removes subglandular implants after many years may find that the breast looks noticeably deflated compared to how it appeared before augmentation, because the native tissue has thinned under the implant’s pressure.
Nipple Sensation After Surgery
Sensory changes around the nipple and areola are a concern with any breast augmentation, regardless of implant plane. The surgical incision type and location play a significant role: a scoping review of sensation outcomes found that lateralized inframammary incisions (along the crease under the breast, placed toward the side) preserved nipple-areola sensitivity better than centrally placed cuts. The review also noted that the implant plane itself modifies sensation outcomes, though incision type was the more significant variable.14PubMed Central. Comparing Nipple and Areola Sensory Outcomes and Nerve-Related Complications Using Different Incision Types in Breast Augmentation: A Scoping Review
For subglandular placement specifically, the dissection stays above the muscle and generally involves less disruption to the nerve pathways that run through the chest wall. In theory, that should protect sensation somewhat. But the nerve that supplies the nipple (the fourth intercostal nerve) can be stretched or compressed during pocket creation regardless of plane, and larger implants increase the risk of stretch-related numbness. In practice, most patients with either placement experience temporary changes in nipple sensation, with the majority seeing improvement over six to twelve months.
Revision Rates and What Drives Them
Breast augmentation is not always a one-time surgery. Revision rates after primary augmentation have been reported as high as 36%, driven by capsular contracture, implant malposition, and ptosis (sagging) of the breast as it ages around the implant.15Thieme / PubMed Central. Revision Breast Augmentation Subglandular patients may face the compounding effect of higher capsular contracture rates and progressive tissue thinning, both of which can prompt a revision.
When revision does become necessary, a common approach is to convert from subglandular to submuscular placement. This involves repositioning the implant beneath the pectoralis muscle to gain additional soft tissue coverage and, hopefully, reduce the risk of recurrent contracture. Some surgeons preserve portions of the existing capsule during this conversion to maintain pocket integrity, though the specifics of technique vary. One pilot study that evaluated patient-reported outcomes with a validated questionnaire found that submuscular positioning was associated with a higher breast shape satisfaction score compared to subglandular positioning, which may reflect both the aesthetic benefits of the muscle layer and the lower complication rates over time.16Aesthetic Surgery Journal Open Forum. A Pilot Study Evaluation of 3-Dimensional Imaging in Cosmetic Breast Augmentation: Results of a Single Surgeon 3.5-Year Retrospective Study Using the BREAST-Q Questionnaire
Prepectoral Reconstruction and the Modern Revival
The conversation about subglandular-style placement has shifted in recent years, especially in breast reconstruction after mastectomy. “Prepectoral” reconstruction is essentially a modern iteration of the subglandular concept: the implant goes in front of the muscle, sparing the pectoralis entirely. This approach has gained traction because improvements in mastectomy skin flap quality and the availability of acellular dermal matrices (ADMs) have addressed some of the historical drawbacks of above-muscle placement.
ADMs are biological scaffolds, typically derived from donated human or animal tissue, that a surgeon wraps around the implant to provide support, cushion the implant edges, and reduce the direct pressure on the skin. A review of ADM evolution noted that these materials have enabled both dual-plane and prepectoral approaches to achieve good cosmetic outcomes with low complication rates.17PubMed Central. The use of acellular dermal matrix in breast reconstruction: evolution of techniques over 2 decades However, ADMs are expensive and not without their own issues. A meta-analysis comparing prepectoral reconstruction with and without ADM found no significant difference in overall complication rates between the two groups, though the data is still limited to small, single-institution studies.18Journal of Plastic, Reconstructive & Aesthetic Surgery. Prepectoral breast reconstruction with and without acellular dermal matrix: A systematic review and meta-analysis
The renewed interest in prepectoral reconstruction is largely driven by the desire to avoid animation deformity, which is particularly distressing for reconstruction patients who may already be coping with the emotional toll of mastectomy. In the reconstruction setting, the argument for keeping the muscle intact is arguably stronger than in cosmetic augmentation, since pectoralis disruption can affect shoulder function and recovery.
Implant Surface and Capsule Biology
The surface texture of the implant interacts with the body differently depending on the type. Textured implants were originally designed to reduce capsular contracture by encouraging tissue to grow into the implant surface, theoretically keeping the capsule from tightening. Polyurethane-coated implants take this further. An animal study comparing polyurethane-coated silicone implants to standard textured implants found that capsules around the polyurethane-coated devices were significantly thicker, more cellular, and more vascularized, with higher levels of growth factors compared to the textured implants.19Plastic and Reconstructive Surgery. Vascular Endothelial Growth Factor Overexpression Positively Modulates the Characteristics of Periprosthetic Tissue of Polyurethane-Coated Silicone Breast Implant in Rats The textured implants, by contrast, developed capsules with more organized, parallel collagen fibers and less inflammation.
What this means for subglandular patients specifically is that implant surface choice may partially offset some of the plane-related risk. A polyurethane-coated implant in the subglandular space, for instance, appears to provoke a different biological response than a smooth or standard textured device. That said, polyurethane implants are not available everywhere and have their own controversy regarding long-term safety and the breakdown products of the coating material. The choice of implant surface adds yet another variable to an already complex decision matrix that includes plane, size, incision approach, and individual anatomy.
For patients weighing subglandular placement, the decision ultimately comes down to a series of trade-offs that no single metric can resolve. Favorable anatomy, realistic expectations about long-term tissue change, willingness to stay on top of mammographic screening, and honest conversation with a surgeon about what revision might look like down the road all play into whether above-the-muscle placement makes sense for a particular individual.