Breast augmentation
The modern prosthetic breast was invented in 1961, by the American plastic surgeons Thomas Cronin and Frank Gerow, and manufactured by the Dow Corning Corporation; in due course, the first augmentation mammoplasty was performed in 1962. There are five generations of medical device technology for the breast-implant models filled with silicone gel; each generation of breast prosthesis is defined by common model-manufacturing techniques.
Pediatric gynaecology
Some asymmetric breast growth is normal in early adolescence, but asymmetry may be caused by trauma, fibroadenoma, or cysts. Most non-pathological asymmetry resolves spontaneously by the end of puberty; if it does not, surgical intervention is possible. Some adolescents may develop tuberous breasts, wherein the normal fat and glandular tissue grows directly away from the chest due to the adherence of breast fascia to the underlying muscle. Hormone replacement therapy or oral contraceptives are used to encourage outward growth of the breast base. Hypertrophy of breast tissue may or may not be a problem for an individual adolescent; back pain, kyphosis, shoulder pain, and psychologic distress may be cause for breast reduction surgery after development is complete. On the opposite end of the spectrum, breast tissue may not develop for a variety of reasons. The most common cause is low levels of estrogen (hypoestrogenism), which may result from chronic disease, radiation or chemotherapy, Poland syndrome, extreme physical activity, or gonadal dysgenesis. Amastia, which occurs when a child is born without glandular breast tissue, is rare.