It calcifies and turns into bonehttps://biology.stackexchange.com/questions/9015/what-happens-to-the-holes-in-the-skull-where-teeth-were-developing
This is two days old a comment, but I literally just copy pasted your comment into google, clicked on the first thing, and apologies for linking deddit, but it used to have quality answers.https://www.reddit.com/r/explainlikeimfive/s/68lVMvCyB0
This is how they figured out that Cathagians performed sacrifices of their own children