Chinese believes that having pacifiers on all the time with young infants would cause "bux bunny teeth", is that true?

I've heard this from my grandparents too. They always say that long term pacifier use and thumb sucking can cause problems with the proper growth of the mouth and alignment of the teeth. But I reckon there is some truth to this. If you think about it, when baby sucks on his thumb or pacifier, the pressure (not sure if it's the right word) will be emphasized in the middle of the mouth/teeth are and prolonged exposure to this pressure can cause the front teeth to grow outwards (hope that makes sense). Thus, you should discourage your child from pacifier use before he or she gets permanent teeth. It can lead to problems with the front teeth tipping outward or not developing properly.