There are a number of reasons to undergo breast augmentation such as being unhappy with breast size and loss of fullness after weight loss or pregnancy to name a few. [drkimsurgery.com]

In these rare cases, the natural support that holds the breasts to either side collapses because too much connective tissue was removed from the cleavage area. [breslowmd.com]

Postoperative complications included 1 hematoma and 1 seroma (that required ultrasound-guided needle aspiration and no further surgery). Postoperative cleavage between the breasts was achieved, and the patient was satisfied with the result. [ncbi.nlm.nih.gov]

The use of breast implants that are too wide compared to the patient’s natural chest structure can cause synmastia, and women with existing chest deformities have a higher risk of synmastia due to anatomical reasons. [easternshoreplasticsurgery.com]

skin (as the skin can be pulled away from the chest bone) the weakening and stretching of tissue that separates the breasts Breast augmentation patients with chest wall abnormalities are also at a higher risk of developing symmastia. [edelsteincosmetics.com]