Submitted by ok-next-please.
This is actually the skull I was thinking of when I posted the initial illustration of the 7-year-old. :)
If you look towards the back of the lower jaw, you can see the third molars (wisdom teeth) forming. Initial calcification of the wisdom teeth happens between 7-9 years old on the maxilla [upper jaw], and between 8 and 10 years on the mandible [lower jaw], though formation of the root rarely finishes before 16 years old, and can sometimes take until 25 years of age.
My mandibular third molars started coming in at 14. It was annoying getting them out. I wish I’d been part of the 35% of the population that doesn’t even develop them!