Dean has started to be able to lift himself up and turn his head when he's lying on his stomach. Once he turns his head to the left it looks like he might get stuck and he doesn't turn his head back to the right very well. A couple of times it looked like he might end up with his face down in the mattress, so we've started him sleeping on his back again. He still sleeps pretty well, although not as well as he used to.
My friend Brixie made me some things that have been very useful. They are posted in the picture above. They are very heavy, the outside is a very soft material and I think they are filled with rice although I'm not sure. They not only keep Dean in place really well, but they also make it possible to prop Dean on his side a little bit so he doesn't always have the same side of his head on the mattress. If you remember I said that Dean is getting a flat spot on one side of his head. He seems to eventually wriggle himself back to the side he likes, but I think his flat spot would be worse if we didn't have these to turn him the other way a little bit. Thanks Brixie! They have been very cool.