Pat was 3 days shy of turning 4 months.
Ashley was 6 months.
Sean was 8 months.
There really isn't a typical time.
I noticed that for each of my kids the age at which the first tooth came correlated to when they grew in. My oldest lost his first tooth around 4, which is a bit early. My youngest lost his first tooth around 7. My daughter was somewhere in between. I don't remember exactly how old, probably 6, but I remember exactly where we were and what we were doing because my SIL helped her by pulling it out. Gah! so much blood.
There's no such thing as global warming. Chuck Norris was cold so he turned up the sun.