I'm going to also throw anecdotes into the bucket: three dentists completely missed a cavity on one of my rear molars (wisdom teeth) until I mentioned pain, and then they poked around physically and said, "oh yeah, that's a big one."
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Then I mentioned I had pain around the crown whenever I ate something sweet or sour. The dentist took another look and said "oh yeah the crown is cracked"
So now I know I either have a cracked crown or I don't. Great service.