Do yours?
No, after the cat is fully grown - be that 18 months or 3 years the teeth are done. If it looks like it's getting longer it may be signs of a dental issue that needs to be dealt with.
I think the key word is 'he'. My observations over the years have shown that male cats just plain have longer canines, frequently protruding over the bottom lip, than females. Dentition in animals is genetic - male dogs have more teeth than females, male horses have more, male cats seem to have longer canines and castration doesn't impair tooth growth, species with more teeth still get them, those with long canines still get them and it does take some time for them to grow. If you are worried, do see a vet - was worried about Jack because he is my miniature sabre tooth tiger and his gums are just fine teeth are fine, canines are just long.
Male cats may have longer teeth, but a change as an adult can be a serious issue and be a sign of serious dental issues which can lead to associated illnesses