National Geographic online is running a news story describing a new study of Neandertal dental development. The study is by Debbie Guatelli-Steinberg and collaborators and is supposed to be in PNAS early edition, but it isn't yet. When it gets there I'll post again. In the meantime:
The question of whether Neandertals, who died out some 35,000 years ago, shared the prolonged childhoods found in modern humans is a controversial one.
Other researchers who studied Neandertal tooth remains reported in 2004 that Neandertals became sexually mature adults by as young as 15 years of age (see "Neandertals Were Fully Developed by Age 15, Experts Say"). The 2004 study found Neandertal wisdom teeth grew 15 percent faster than those of modern humans.
Guatelli-Steinberg, though, says the earlier study did not take into account how variable modern populations are in their dental growth -- a criticism that was also raised at the time of the 2004 study's publication.
"We examined a much broader range of modern humans, from three different regions of the world," the anthropologist added. "When we did this we found that Neandertal [front teeth] formation spans are comparable to those of modern humans."
Personally, I think we have a long way to go in understanding the variation in growth rates in living people, before we can infer that Neandertals are very different from us in the sequence and timing of growth. That seems like it's going to be the conclusion of this work, so that sounds about right to me. This doesn't tell the whole story of Neandertal development, but it does help to establish a timeline. And teeth have a much bigger sample than the kinds of artificial growth-series of crania (from different times and places) that we are starting to see.