Just to add to that, yes raw bones are the best possible thing you can give your dog to chew on. That's what nature intended dogs to eat, and spent 45 million years or so designing them specifically for.
What dogs are NOT designed to consume are hunks of bacteria-leaden leather - otherwise known as rawhides and pigs ears. If you were to do a search of the forums, you'd find several hundred threads about dogs who have choked on those things (and some who've died as a result). You'd find very few about dogs who've had problems with natural raw bones though.
That is not the only problem with raw hide/pigs ears. They are chemically cleaned to remove the hair - and that means your dog is ingesting all those chemicals when they chew on them. They frequently cause impactions/blockages when swallowed, becuase they are indigestible. And on those occassions when the dog swallows bits of those things without either choking or suffering a blockage, the bacteria-laden leather sits around in the gut for days or even weeks causing bacterial poisoning (which is why so many dogs end up with diarrhoea and vomitting after consuming raw hide).
Really, they are nasty, nasty things to let your dog chew on. Better avoided completely.