My 5 yr old has been having "Night Terrors" every night

I would talk to his pediatrician if you suspect night terrors. There's no way for anything or anyone over the internet to make that diagnosis or to really tell you what is going on.

I can say that I used to grind my teeth a lot as a child and it was something that continued into adulthood. I had a very stressful childhood and didn't grow up with a great family and that is how my stress manifested itself. (Of course, I'm not saying that's what's going on with your son!) You should also talk to his ped. about getting him a night guard so that he doesn't start grinding down his teeth. Even if the wakings stop the grinding may not.

And, my almost 3 year old daughter wakes up crying frequently. There is nothing traumatic going on, nothing stressful. Sometimes kids have bad dreams and sometimes it happens a lot. It's usually a product of their active imaginations and will stop on its own. But, a chat with the doctor is never a bad idea.