> CMIIW, but when baby teeth is already grown (appear), the other adult set is actually kept hidden inside, not that it grow.
Yup. See this skull of a child with the adult teeth ready to come out and push the baby teeth out of the way (warning, some people find the image very repulsive, even though it's basically a textbook picture of a skull):
The human body is so amazing... It evolved to ship ready-made replacement parts to ensure the product would complete its deployment (reaching puberty and reproducing for a decade or two).
I think it comes off as more repulsive because we're not used to seeing those parts of the skull cut away, putting it in the uncanny valley. What helped me to not be as repulsed by it was realizing that those parts of the skull aren't meant to be "uncovered" to show the adult teeth in the first place.
Yup. See this skull of a child with the adult teeth ready to come out and push the baby teeth out of the way (warning, some people find the image very repulsive, even though it's basically a textbook picture of a skull):
https://skeptics.stackexchange.com/questions/9541/is-this-im...