hamster teeth are shockingly long, if hammies eating/cleaning and managing without any apparent difficulties then they not too long, on older syrians ive seen the top ones up to about 15 and they stil ben "normal"
check ham for sores/ulcers in mouth, if teeth ar etoo long theyll dig in and hurt, and hammie wouldnt be happy and healthy
is the hammie chewing chew toys or cage bars? coz if its the cage bars thats hamster language for "i wanna come out NOW!"
lol
even if they do get too long ull know in plenty of time to get them cut, its possible for u to do it with the right tools, but id recommend vets if cutting is normal, coz hammie wont likie it, if ur really worried u can buy mineral blocks from pet shop that act as gnawing blocks.
im sure hammies fine, hed let you know if he wasnt 
xxx pixi