Why are SOME people blessed with "good teeth"?

I know a few people that have never or rarely had professional oral care and they're teeth look "perfect". One or two cavities, straight teeth, never a major problem with their teeth. And then there are people like me who have suffered w/dental problems despite seeing a dentist on a regular basis. Is it soley based on one's diet? Or do genes play a role too?
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It's a combination of genetics and hygeine. There are some people who have terrible teeth because they simply do not brush their teeth, floss, and constantly eat sugary foods. Others may take excellent care of their teeth, yet their genetic makeup determined the strength, size, proportion, and order of their teeth. It sucks... but no fault lies in the second person I described. It's just the way it is.
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