Is it normal for 2 years old still thumbsucking? I'm afraid it affect my kid teeth development. :(

It's definitely a normal occurrence for a two-year-old to be thumb sucking. In fact, babies are sucking their thumbs as early as life in the womb. The problem with thumb sucking is that it is difficult to wean your child off of the habit. Be cautious of this! It won't stunt their development or anything of that nature. Though, it's highly recommended that you break their habit by age four at the latest. It can be very bad for their teeth and gums! http://ph.theasianparent.com/pacifier-vs-thumb-guide-parents/2/