Yes.  A female colleague asked me "Do the people in the bathroom not look at you weird?"  To be honest I haven't noticed.  It's not like our bathroom is constantly full of people so sometimes there's no one in while I'm brushing.  But her question made me think maybe people would find it a little strange. 

Glad to see I am not the only  one!

I have a traveling toothbrush in its case and I use it after every meal.

Some stare, some even laugh, but I dont care. My grandmother had all her teeth when she passed away at 89 by taking care of them, so I plan on doing the same.

I don't even brush my teeth. I just go full-Mao, like half of Hunan. Anyone want to see my green slime?

LOL I did before at a school. I don't anymore. The reaction? There was no reaction! 

Yes, like 3 times per day. I see the other Chinese teachers doing it as well as all the children every time they're having a meal. 

I don't do it myself but I've seen many Chinese brushing their teeth after lunch (at work)
... I don't think it's uncommon... those who laugh are the ones that giggle when someone say "penis".

 I do it after every meal. I don't eat at school, I cook my meals in my dorm.  If i happen to eat out, I brush my teeth.