I have twin boys that are 9 mths old. One has 6 teeth (4 upper and 2 lower), and the other one has not a single one that has come thru yet! But that doesn't keep him from chewing on everything he can find! lol... actually, the one without teeth seems happier about chewing bits of food than the one WITH teeth! Go figure... ;-) They all go thru things at their own rate, so I wouldn't worry about it too much. Be careful about sweets though, my aunt gave my cousin juices and kool-aid in her bottles (who would do that??!!) and she didn't have teeth until she was almost two and the ones that came in had major cavities. Needless to say, she is now an adult and has had severe dental problems her entire life.