Extra teeth?

I took Patience and Flower in for their annuals today. The vet found and showed me that Flower has an extra tooth - it's an incisor, right behind the upper canine on her left side. The vet didn't say anything about it needing to be removed or causing any problems - there's plenty of room there. She's over a year old so it's not a milk tooth. I was just wondering how common or uncommon extra teeth are and if it may cause a problem as she gets older?

One of my females Molly has the same thing, the Vet said it was nothing at all to worry about, it was just an observation more than anything else. She is 3 1/2 years old and it doesn't bother her a bit.

Thanks! I wish I had known about it earlier, I could have checked Flower's littermates to see if any of them had an extra tooth too.

Maybe they don't, Molly was in a litter of four and none of the others have it.