Braces help! Payment!?

Okay, I've had braces for 1 year now and need them for another few months. The thing is I'm broke. Lol. But I've been paying 180 per month till now, and I owe them only 500 bucks. Yea that's it. 500 bucks, and total was 3400. My orthodontist is really nice and I'm wondering what happens if I stop paying this month or next month. Is their a way we can work things out? Give me your opinion please! Thanks