There are some problems, none is really unsolveable, but all together tend to restrict this

1. one brain is more than enough - so a multiheaded species will probably not have it's brain in it's head (although dinosaurs having two brains is probably bullshit, a species COULD carry it's brain somewhere else)
2. having your brain separated from main sensory organs (i.e. eyes) tends to complicate things - but there are insects with stalk eyes and similar that solve this problem
3. having secondary digestive entrance is probably the worst problem - I don't really think there will ever be something that has more than one fully functional mouth attached to it's "heads"

so don't make it have it's mouth on the heads and brain contained in it - make it specialized limbs that come with eyes/ears/whatever and place the mouth somewhere on the main body.

That doesn't need those head/hands to not have teeth - or at least something like lobster claws to rip stuff appart instead of chewing.

There are some problems, none is really unsolveable, but all together tend to restrict this:

1. One brain is more than enough, so a multiheaded species will probably not have its brain in its head (although dinosaurs having two brains is probably bullshit, a species COULD carry its brain somewhere else);
2. Having your brain separated from main sensory organs (e.g. eyes) tends to complicate things, but there are insects with stalk eyes and similar that solve this problem;
3. Having secondary digestive entrance is probably the worst problem; I don't really think there will ever be something that has more than one fully functional mouth attached to its "heads".

So don't make it have its mouth on the heads and brain contained in it - make it specialized limbs that come with eyes/ears/whatever and place the mouth somewhere on the main body.

That doesn't need those head/hands to not have teeth, or at least something like lobster claws to rip stuff apart instead of chewing.