I can help with both issues. The teeth grinding is very normal at that age. They are getting used to the feel of them, they are actually soothed (much to our ears displeasure) but the feel of them rubbing together. I was told by my ped. dentist that I should nothing. Just allow him to explore this sensation. They will grow out of it. It could also be that he is noticing the discomfort of new teeth coming in and he can only generalize the area that the sensation is coming from.
Next my Ped. is a firm believer that children need to learn how to put themselves to sleep on there own (thank God)
This will take about 7-10 nights but it will work! First night he wakes up go to him and do not pick him up, do not change him unless he has pooped, do not turn on the light. Lay him on his back and rub his tummy, tell him it is night-night and time to sleep. Do this each and everytime he wakes up through the night. Second night let him cry 5 minutes before you go to him and do the exact same thing as the first night. He will get the message that it is sleep time. Continue this EVERY time he wakes up in the night.
Good Luck, This has made a world of difference in my son's sleeping.
-B.