Hanging on by a thread

Ethan has been telling me for several weeks now that he has a wobbly tooth.  However, when he tried to show me, I couldn't find any which seemed loose.  However this evening he came running through to me in tears, after trying to eat an apple, saying his tooth hurt.  When I checked, one of them was hanging on by a thread, although you can't really tell in this picture which one it is!  Looks like he shall shortly be loosing his first tooth - hope it doesn't fall out during the middle of the night!