I only got my braces because without them, my TMJ would get to the point where my jaw would not work. TMJ is when the joint in your jaw gets grinded down. Mine is at the point where my joint was gone and my jaw was held together with the muscle alone.
Every time I went to open my mouth, my jaw would lock and I would have to 'unhinge' or dislocate my jaw manually. It was painful. The braces and a jaw wire helped...