My facial structure changed slightly. The only people who really noticed were
my sister, my mother, and me (after they pointed it out to me). My face was
always very round before braces, but over the course of two years, my jaw
elongated a bit, which made my lips appear fuller (even after the braces were
removed) instead of sunken in.

Oh, and the best part was when I got them off, I had a smile I could be proud
of, instead of snaggletooth overbite.

So you may have minor facial changes, but most likely you will find them to be
an improvement.