White square on teeth after your braces?

Is it true? I've heard a BUNCH of people say that, including some of the nurses that work at the Orthodontist office said that. Before I say anything else, I'm not the one worried about it. I brush my teeth often, not as much as I should (I know, its a habit) and I knocked a few brackets off (sports) and there's nothing wrong with my teeth. I was wondering if its true. Let me rephrase that, I know it could happen, but is it true that it can't be fixed? That's what they all said. I personally think it can be fixed, I just think its their way of getting you to brush. I heard someone say that it happened to his brother, but the orthodontist gave him a special cleaning for an additional charge... So, whatya think?