If i get a boob job at 18 will they disfigure as i get older?

Gravity never quits: Gravity and time alter everything, but don't let that stop you. Talk to a reputable board certified plastic surgeon. They can guide you.

Breasts change: Constantly and if you start any activities that are known to contribute to man boobs, you could still have growth after an initial treatment but much depends on how your initial treatment was done.