the main difficulyt is the teeth bleach out and it's harder to tell dentine from enamel.
Exactly. But aging of very old jawbones is possible. Archeologists and paleontologists can age deer from jawbones that have been in the ground for thousands of years.
"Know where you stand, and stand there" --Jesuit Father Daniel Berrigan
"There is no reasoning someone out of a position he has not reasoned himself into." --Clive James