Most children's crooked teeth are caused by puffed food. Puffed food such as French fries and potato chips are too easy to chew, and they contain a large amount of sugar and salt, which are harmful to teeth. It is not advisable to always feed children with fine food. Many parents only allow their children to eat soft food that melts in the mouth or can be chewed in a few bites. We advocate chewing each bite of food at least 10 times.