This procedure was also reserved for those over the age of 18, but nowadays the number of teenage girls getting breast implants is steadily increasing. Last year, over 1,800 girls under the age of 18 had their breasts augmented. There are no major physical criteria that would restrict a girl from breast enlargement surgery. The only requirement is that the girl has completed her growth, which usually occurs by the time she is 16, and often earlier.
Psychological criteria are another question.
There is a relationship between body image and depression. Negative attitudes about one's appearance can be a symptom of depression. Body dysmorphic disorder is a mental illness characterized by self-loathing of one's physical characteristics. Needless to say, psychologically normal teens are self-conscious, and commonly dislike their appearance. Plastic surgeons are supposed to screen all patients on psychological criteria as well as physical.