I've been sick in China once and went to a Chinese medicine shop. They doctor told me to open my mouth and asked the nurse what it looked like- he was pretty much blind. Then he prescribed some herbs to mix and make Chinese Medicinal Tea with. It tasted like arse but did the trick.
If you have a tooth ache, waiting until you get to Xi'an might not be such a good idea!
(this is the view from one of the busier streets)