[czen]

Ortho here is so expensive.

[jayinhongkong]

Originally Posted by PDLM

I remember reading, though it might take me a while to find it again, that the "grey teeth" thing is to do with over-use of certain antibiotics (that were common in HK several years ago) in childhood. There are certainly plenty of locals around who don't have them as well.

Edit: found it - http://en.wikipedia.org/wiki/Tetracycline_antibiotics

Even the mother taking them in pregnancy can cause the problem.

Tetracycline can do that, but not everyone gets tetracycline. A lot of the 'grey teeth' here are caused by something else entirely: decay. Tetracycline is still used AFAIK. I was on a course a few years ago.