Despite good oral hygiene, some children have weak teeth that are more prone to decay.
Puppies and kittens are born without teeth, but by around two months of age they have a full set of baby teeth.
If an undocumented migrant is a minor or an adult can have far-reaching implications. A forensic anthropologist explains why relying solely on dental X-rays to determine age doesn't work.
Even those who regularly clean their teeth typically don't brush for the recommended two minutes.
Beyond the shiny cartoon characters and bubble gum flavouring, there's little reason to buy these products – and often several reasons not to.