system
Given the following post, respond as if you're commenting on Reddit:
human
What makes teeth come up through the gums?

I've got a little baby who is teething, and I'm just wondering why teeth are there dormant but come up at such a range of times. Anywhere from 3 months to a year old for the first ones, and then on from there. What biological nudge is the body getting for these teeth to erupt? And again for adult teeth?
gpt
There’s actually little agreement among the dental scientific community on what the actual force is that causes tooth eruption. 

Teeth begin as little buds, like flowers, and develop in a sac, slowly laying down calcium and developing nerve tissue and vascularity.

When the time is right, cellular signaling begins the process of moving the tooth into the oral cavity. Some think the surrounding developing bone plays a role, or the periodontal ligament (the PDL), or both. The PDL holds teeth in the socket and is separated when removing (extracting) teeth.