I think doctors can forget how what they say affects patients. So many of them are just really into what they do and get genuinely excited to see something unique. I would bet that's why he mentioned that. It doesn't have to be something bad just because it's rare!

I have all of my wisdom teeth in my mouth and one of them is only like this little mini half tooth. My dentist recently sent me for a evaluation with an oral surgeon to see if I needed a root canal on one of my teeth and the guy was so into my tiny tooth, haha. He kept bringing people in to look at the x-ray and they were all, "WHAT IS THAT?!" I try to take it as a sign I have a good doctor/dentist/etc... who really has passion for his work!