Sensory Integration and Loosing Teeth?

It may be that he is that sensitive. Have you taken him to the dentist? Are there any other situations that are happening right now that could be causing him to lose sleep? You want to examine that first - could there be some things that happen at bedtime that cause him anxiety? If not, it may be that he is hypersensitive to that bottom tooth, and then maybe you can find out how that tooth can be soothed at night - whether by some kind of teether, your presence, or something more. Hope that helps in some small way.