[Fluffagrams]

From the angle of the photo, it's difficult to tell whether his teeth are too long. Can you scruff him to get a photo of his teeth that way?

In terms of what can help, I have found that none of my hamsters have bothered with the wooden chews that pet shops often sell for this purpose and I have had better luck with dog biscuits or dog chews. Whimzees is the most popular option of dog chew but Antos chews are (I think) pretty similar.