It was in a Swedish paper interview three or four years back. He had his wisdom teeth removed at the same time and talked a bit about how statistics showed that they could cause a problem later on in his career, so he had them pulled as soon as his schedule permitted it and then spent most of the summer lying in bed. I'll see if I can find it.
I'm not sure the adjustment as such achieved much at all in terms of performance. I think it was more of a comfort thing, possibly related to heavy training where you tend to clench your teeth together.
