Hi T.
There are two things I suggest:
1) U need to first establish a firm, consistent bedtime routine. I went on www.babycenter.com and researched routines used by other moms, and came up with my own. I am so consistent with the routine. It took her 4 nights to learn waht the routine meant.
The routine allows for them to learn how to put themselves to sleep, and back to sleep. Rocking, music, etc may be fine when they go to sleep, but they wake up in the middle of the night and then can't put themselves back to sleep, b/c the rocking, music, etc is not there... The routine teaches them that "this is now bedtime" and mentally they know what is coming. Babies and toddlers thrive on routine and they're much happier and calmer overall.
2) As for waking up early, my daughter started doing that 2 weeks ago. She was getting up at 4 am too, also due to teething. Once she was done cutting her teeth and there was no excuse for waking up, we used the cry it out method. By the 4th night she learned mama isn't coming back to play or take her out of the crib.
I think once your son's molars finish cutting through, he'll feel better. However, the habit of waking up will probably remain, so that's where u need to teach him good habits again. I also feel Motrin works tons better than Tylenol, and more longer lasting. The twilight feeding suggested sounds good too, however, be warned he may come to expect those few sips of water and wake up waiting for you.
I know crying it out may sound harsh, but it is a sure-fire way for them to learn to put themselves to sleep. Are babies mentally scarred from crying it out when they get older? It has no effect on them and it teaches a very necessary habit. Crying it out is hard on parents, that is why it's so underrated. Do you remember crying when u were in the crib for mama who wouldn't come? Babies learn very fast. In the end, they, and you, sleep well. Good luck.