Your Smile is Uniquely You!
Like a fingerprint, your set of teeth is like no one else's. Even twins will have variations between their two sets of teeth - urm, especially if they treat their teeth totally differently! LOL, this study said, "...even so-called identical twins are in fact not dentally identical."
Yup, it sounds like a random dental fact that'll come up when people hit a lull in their conversation or like a winning clue on a popular game show, but it can actually be useful to know.
One use for this info is in forensic dentistry.
Unidentifiable victims (e.g. if their face/body was badly burned, etc) can sometimes be identified by comparing the dentition of the remains with existing dental records. (Now that we've thoroughly made everyone uncomfortable - is it a good time to place a shameless plug in here - you know, to update your dental records just in case?)
But even if a forensic dentist didn't have access to a person's dental chart, they're still able to draw information from studying what is there. They can tell if there are any missing teeth. They can tell whether or not someone smoked. (You know, kinda like how we can tell whether you've *really flossed or not 🙃). And, DNA can also be extracted from teeth. Which then can all be compared to existing records.
What's not always consistent though, are bite marks as credible evidence against a perpetrator in court. Similar to how a bite impression might get distorted in the making at the dental office, someone who bites a victim may not be biting straight on, they might be at an angle and not all the teeth may make contact. There are so many variable factors that it just doesn't make it cut-and-dry concrete evidence.