What is Symmastia or “Uniboob”?

Symmastia is a condition where the two female breasts meet in the middle. Typically, the female anatomy situates a flat area between the breasts and above the midline sternal or chest bone. However, in rare cases seen in normal females, the breasts can meet in the midline but the skin remains attached to the underlying bone. When symmastia is created because of a breast augmentation, the breasts not only appear to meet in the middle, but – in many cases – the skin over the sternal bone is actually lifted upwards so that the cleavage area is floating off the chest bone. The appearance of this condition is usually not so odd that it is obvious to the human eye at first glance, but when more carefully examined it is certainly not normal.

What Causes Symmastia?

Symmastia is something that is far too common after a breast augmentation. The most likely cause is the use of breast implants that are too large for your chest dimensions (they simply don’t fit on your chest). In this case, the breast implants will expand over the midline of the chest and touch the other side; the cleavage area looks odd and is elevated off the sternal bone. If your surgeon over dissects the implant pocket in the midline this can also certainly lead to symmastia as there is no normal anatomy to keep the implants separated. Women who have a concave-shaped chest (funnel chest or sunken chest) are at higher risk for symmastia as this shape allows the breast implants to settle towards the midline of the chest. The typical female chest anatomy is sloped towards the sides (away from the sternal bone) so that breast implants are most likely to move to the side or down with time.

Symmastia Repair

The treatment of symmastia can be challenging. A “thong bra” is unlikely to separate the breasts once true symmastia is established. The tissue of the midline of the chest needs to be moved back down to the chest bone and secured with or without the help of acellular dermal matrix (a type of tissue used to build a new “internal bra” that keeps the breast implants separated from the midline). It is often advisable to select smaller breast implants if the primary cause of symmastia was the selection of overly large implants to begin with.

What It Looks Like When Breasts Touch In The Middle

I have had much success in the treatment of symmastia internally with the use of innovative suture techniques as well as the use of higher profile breast implants that actually allow for larger sizes if desired. It’s important for the patient to wear an appropriate bra after treatment to minimize the potential for recurrence of the symmastia. Patient satisfaction has been quite high with the creation of normal appearing breasts with beautiful, natural-looking cleavage.

Most importantly, make sure that your surgeon is familiar with breast augmentation and that you choose an implant size and dimension that will fit your anatomy. If you are at higher risk of developing this condition because of your chest wall anatomy, make sure you wear an appropriate bra to keep your implants where they need to be. An ounce of prevention is worth a pound of cure!

Do I Have Symmastia? How To Diagnose And Treat Symmastia

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