Owen's mother is thought dead. Not sure he believes what he was told about that though.
Regnus's parents are dead. They were killed right in front of him.
When Dargos left, his parents were alive, but they were ashamed of him so he doesnt really acknowledge them. Actually Dargos is insane anyway and doesnt really remember much of that time other than the ridicule he got for being an unskilled dwarven miner. hehe