Dogs are capable of acting aggressively without always attacking. This common dog behavior problem is often caused by your dog showing teeth, growling or barking as a subtle demonstration of aggressiveness.
It doesn't mean that any tendency for your dog to exhibit aggressive behavior is acceptable, especially if this aggression frequently targets the owner or family members. First of all, you should never deal with an aggressive dog by yourself - if possible, hire a professional dog trainer who has experience dealing with this type of dog.
Otherwise, proceed cautiously. Set limits on how capricious your dogs can be and emphasize to them that they don't control the situation. Ignore their poor and aggressive behavior and use positive reinforcement.
Monitor the progress of your pet's aggression. If none of the obedience training, setting limits, reinforcing positive behavior methods work to deal with this problem, talk to the vet and a professional dog trainer. The only way your dog can learn how to live among people is through professional care such as a dog trainer.