According to this article: Discovery Channel :: News :: Mutant Chickens Grow Teeth, chickens have the potential to grow teeth. Previously scientist have been able to make chicken grow teeth by adding tissue from other animals, but the methodology for this experiment demonstrates that the potential to form teeth are part of the embryonic development of the chicken.
I have always heard that the velociraptor and T-rex were probably related to birds. This at least demonstrates a possible connection.
I don't think I want to meet a chicken with teeth though!