My DS6 started getting his teeth at 4 months, had all of them that he was due at two years by the time he was 1, and didn't start losing them until 6 1/2. He'll be 7 in just over a month, and he's still only lost the first two. I expected him to lose them early, as early as he got them, but it didn't happen that way. His friend next door is over a year younger than he is, and she's lost at least 4 teeth already! I guess you just never know.