Symmastia is a cosmetically undesirable circumstance in patients with breast implants which occurs when implants come too close to the midline of the chest. This results in a lifting of the skin from the chest wall and creates the dreaded unaboob appearance; This usually happens as a result of the overly-aggressive release of the chest muscle during implant surgery, extending the release to the mid-chest.
Correction of this condition via breast revision surgery usually involves removing the implants and closing the space in the middle of the chest with internal sutures. This approach works best when implants remain out of the body for a period of time after surgery and are then reinserted after approximately 12 weeks (or more), allowing the body time to heal. If the implants are replaced too soon following the corrective procedure, the effects of gravity and pressure of daily activities may cause the problem to recur.

