Horrible Sounds

Argh! Help! I sit here at quarter to 9 in the morning (after my baby slept through the night but of course I didn't fall asleep until quarter to 3) with Jonah, just chilling. And he makes such a horrific sound - like he is chewing on his teeth. And then I realized oh no, he has learned how to grind his teeth. Mind you, he only has 2 whole teeth and 2 half teeth, and one quarter of a tooth but they are right on top of each other and he grates them together. I've never really been around anyone who grinds their teeth and therefore I never knew how much I hate the noise. But every time he does it, I freak out and then Jonah laughs. Right, so I know that certainly isn't the way to handle it. But does anyone know how to nip this in the bud???? Do I call the pediatrician? The dentist?? Or am I doomed to live with this noise until the dentist says Jonah has to wear a mouth thingy because he has been grinding his teeth for years and years.
Anywhoo, I hope to hear your comments and maybe someone has a miraculous way to stop it (riiiight....along with getting him to always sleep through the night , not bang his toys on the glass topped coffee table, and lean his head back in the bathtub so I can rinse off his shampoo).
Love you all, Natalie