Symmastia ("Uniboob") In Austin, TX

Symmastia is a condition where the breast implants — or, in rare congenital cases, natural breast tissue — appear to touch or merge across the midline of the chest, above the sternum. Normal female anatomy has a flat, defined area between the breasts. In symmastia, that division disappears: the skin over the breastbone lifts and floats forward with the implants, and the cleavage area looks elevated and continuous rather than separated. It's commonly called "uniboob."

It's not always dramatic. Mild cases can go unnoticed at a glance and only become clear on closer exam. But once it's established, it doesn't correct itself, and it isn't something a bra alone can fix.

Symmastia after breast augmentation almost always traces back to one of a few things:

• Implants too large for the chest dimensions. This is the most common cause. When an implant doesn't fit the width of the chest, it expands toward the midline and pushes past where it should stop.
• Over-dissection of the implant pocket. If the surgical pocket is opened too far medially, there's no longer any natural tissue holding the implants apart — surgeon technique, not implant choice, is the driver here.
• Chest wall shape. Women with a concave or "funnel" chest are at higher risk, because that anatomy naturally slopes implants toward the center rather than out to the sides. A typical chest wall slopes away from the sternum, which is what normally keeps implants from migrating inward.
• Side-sleeping. This can shift an implant toward the midline over time, but it's almost always one-sided — true bilateral symmastia from sleep position alone is unlikely.
• Notably, implant type isn't a factor. Saline vs. silicone, round vs. shaped, smooth vs. textured — none of it changes symmastia risk. This is a fit-and-technique issue, not a device issue.

Symmastia is largely preventable. Choosing implant dimensions that actually match your chest wall — rather than sizing to a target cup size alone — and working with a surgeon experienced in breast augmentation and revision are the two biggest levers. If your chest anatomy puts you at elevated risk, appropriate post-operative bra support in the early healing period matters too.

Robert Caridi, MD Diplomate, American Board of Plastic Surgery Fellow, American College of Surgeons (FACS) Member, American Society of Plastic Surgeons (ASPS) Member, American Society for Aesthetic Plastic Surgery Founder, Austin Gynecomastia Center