Not all cats have the same size teeth just as people. I have a cat who's canines stick out of his mouth. He just has very large teeth. I did ask the vet at one time, and I got a giggle and was told the very same thing
Just wondered in case it was something diet related, like not enough dry food or something to grind them down a bit a guess. Not that he's a rat or anything!!! Guess he just has big teeth like his mummy had before she grew into them! LOL!!
The canine teeth (the long ones) do not get ground down from eating. Cats actually swallow most of their food whole, with some cracking of hard bits with their back teeth to make them easier to swallow whole. Cats don't have flat molars with with to grind and chew food like people do.
Your cat likely has not grown into his teeth yet. His head will likely grow some more. Similar to how children look like they have such big teeth when their adult teeth first come in, but still have little children heads.