Plastic is taken from the Greek word "plastikos", which means
"to mold."
In fact, “plastic” surgery predates the introduction of “plastic” materials.
During residency training, plastic surgeons are trained in techniques to repair or rebuild body defects caused by injury, disease, or a birth defect, such as a cleft lip. Typically, plastic surgery residents have minimal exposure to training in "cosmetic" surgery, which is defined as surgery undertaken to enhance a normal appearance, rather than surgery undertaken in an effort to make a normal appearance out of an abnormal one (such as breast reconstruction after a mastectomy), which would be considered "reconstructive" surgery.
Most plastic surgeons get most of their cosmetic surgery training after their residency, in additional fellowship training and in practice. Most of what I know about cosmetic surgery, I learned after starting practice. Such techniques as laser skin resurfacing, endoscopic forehead lifts, fat injection, ultrasonic liposuction and vertical breast lifts were all introduced or popularized after 1988, the year I finished my residency.
Sometimes, reconstructive plastic surgery and a cosmetic plastic surgery combine. For example, it is not unusual to open a nasal airway at the same time as a rhinoplasty. The patient breathes better and looks better. Will insurance pay? Just for the part of the surgery to improve the airway. A breast reduction can be both functional and cosmetic. It can alleviate back and shoulder pain while improving the appearance of the breasts.