Plastic surgery has become very popular in the US mainly for personal beautification.

Islamically, plastic surgery would be permissible in correcting birth defects like cleft-palate and hair-lips, or reconstruction of missing or deformed limbs.

The Prophet prohibited the plucking of eyebrows, tribal scarring, tattooing and artificial spacing teeth. These are ancient methods of cosmetic surgery most of which have survived in technologically advanced methods until today.

Unnecessary cosmetic surgery is an expression of displeasure with Allah's creation, and would be forbidden in Islam.  Cosmetic surgery is currently used by many to remain youthful looking.