Have you seen the teeth of many people here? Some can use a chopstick rather than a toothpick. Maybe it's the embarrassment of flashing the teeth. I notice that many of the women put a hand over their mouth when they laugh too. Do you think that's related?

I've seen girls here eat the whole chicken, bones and all, every bone!! My teeth ache thinking about it still....that was nearly 3 years ago. What would it be like to be bitten by her??

From my understanding, it stems from the idea that your hands are naturally dirty and you shouldn't put them in your mouth. Using a toothpick comes very close to that, so to be "polite", people will cover their mouths when they do it. It also acts as a shield so if you need to "dig deep", it avoids the possibility of flinging a piece of dislodged food at a person sitting near you.

Just to be helpful, in case people don't know these things, here are some other "Chinese etiquette" tips dealing with dining:

NEVER EVER stick your chopsticks in a bowl of rice so they stand up. This closely resembles incense sticks put in a censer to mourn the dead and is seen as incredibly rude to do at the dinner table, which is usually a festive occasion, even if it's a Monday. Meals are to be enjoyed with friends and family, invoking death is just bad form.

When dining with family or business partners, follow these tips. I'm not 100% sure these are correct, but I've been here for a while and doing these things does show respect:

1. Wait for someone to tell you where to sit. Seating at a table is INCREDIBLY IMPORTANT in Chinese culture and just grabbing a chair is rude.
2. Let elders sit down first. This is a common courtesy and shows respect.
3. Don't start eating as soon as the food gets on the table. The host will usually tell people when to start eating. As the host is also most likely paying for the meal, show respect and let them dictate. Chinese people love to offer food and allowing them the pleasure of basically saying "dig in" or "please eat" is respectful.
4. Eat as much as you can to show you're enjoying the food, BUT, and this is important, DON'T "clean your plate" and finish all the food offered. ALWAYS leave some food on your plate and on the table. Even if you could totally finish off everything. Not having "extra" food left over means the host was not generous enough. I usually try to take more than I can eat simply for this reason. Leave food on your plate and tea in your cup. It means you enjoyed it so much that you want more and appreciate the food and drinks, but simply have had your fill.
5. You should try everything that is offered to you. Even if it's strange by your standards. Not doing so and turning your nose up at something comes across as rude and offensive. Especially if someone says "Try the .....". If there is something you really can't eat, explain the reason politely - "I would love to try that shrimp dish, it looks absolutely delicious! Unfortunately I am allergic to shrimp, so if I eat it, I will become very sick. Thank you for ordering it though, I know it is a special dish. I should have let you know in advance that I cannot eat that, so it is my fault." - honor your host even if you don't like something.
6. Don't take the last pieces from a serving tray. This falls into the category of point #4. If pushed by your host to take it, refuse twice. If they ask again, then take it.
7. Wait until a toast is offered before drinking alcohol, even if it is already poured.
8. It is ok to use your hands to eat some food. Chicken on the bone or peeling shrimp is fine.
9. Try not to get offended if people make noise or burp while eating. In China, this is a sign that people are enjoying the feast. With noodle dishes, Chinese people will slurp them mainly because it helps to cool them down. Also, DON'T cut your noodles with your teeth and/or chopsticks. Noodles are long and represent long life. Cutting a noodle represents "cutting a life short". Use your chopsticks to continually feed the noodles into your mouth until the end. Biting down on a noodle is kind of like a bad omen here.

A lot of these things don't readily apply to foreigners as much. Most Chinese people know you come from a different culture and will "let these things slide". They might even find it amusing - "hahaha, he bites his noodles!". But following these things will help. It shows that you understand the culture here and are doing your best to follow it, and that goes a long way with people here.

CULTURE OR TRADITION NOTHING MORE....

yeah, culture is weird. some things you cant look into too deep.

the logic of using toothpick.....showing that you are full but actually not..putting it on your mouth so that you wont talk much jejeje