Nature's Variety Frozen Raw, how often do I need to add meaty bones to my dog's diet?

[brandikiss]

I've been feeding Nature's Variety Frozen Raw. I hope it is good for my dog. I am wondering though, should I be also giving him raw meaty bones, such as beef marrow bones, chicken necks, and chicken backs? And how often do I need to give him the bones?

I saw on Yahoo Answers someone complaining of feeding their dog the BARF diet and that their dog chipped a tooth from eating bone. Does this happen often? She said it was on a chicken wing. Could this happen from a chicken neck too?