Depending on where OP is from, they may want to contact any indigenous groups nearby. Teeth necklaces aren't uncommon in a lot of cultures including Moari and Native American. If these teeth are real, and belong to one of these groups, they should be returned immediately.
Especially if they are Native American as being in possession of them is illegal and carries jail time.
Also sorry for your loss OP!
Maybe your mom was the tooth fairy?
You can get some decent money off of stuff like that!