I'm so sorry...
I'm not one to label everything "dominance"...as most everyone knows around here. Dominance stuff is mainly crap. Besides, no matter what it is, he's being aggressive. Labeling it doesn't solve the problem...you need training.
What appears to be happening (from what I can gather via what you've posted) sounds similar to how Sawyer was when he first came to me. He's an easily excitable and has little self-control and little bite inhibition. When physically pushed, his response is to use teeth. Why is that? Because dogs use their mouth/teeth to communicate...they use a lot of other stuff too (body language, vocalizations, etc) but they use their mouth/teeth to get their point across with other dogs. Two dogs get in a scuffle...they don't use feet, they use their mouths. My guys are always snapping at each other for things...Sawyer is the worst, he gets greatly offended by physical touching at times...and will grumble and snap at the others. He doesn't do this with people...just the dogs. But all dogs use their teeth to make points...that's how they're made.
When you get a mouthy behavior from him, it seems that you immediately have some form of correction ready...usually physical. Obviously this isn't working...whether or not this is how some folks deal with their dogs, it's obviously not working with Sherman. It's just making his behavior escalate.
Sawyer was very grumbly when I first got him...no history, found as a stray. I would grab his collar and move him away, or push him with my foot, etc. These things worked with the other dogs fine. Not with Sawyer. One day, I went to push him away with my foot (he was encroaching upon my dinner plate, which was on my lap as I sat on the couch). He snapped at my foot. I snapped, jumped up screaming, grabbed him by the collar and started dragging him to a crate downstairs. He mouthed my arm a few times, and I just got more mad. Long story short, he ended up putting a puncture in my forearm...after I yelled and wrestled with him some more. )Very rarely do humans come out the victor in a physical battle of wills with a dog. They have sharp teeth.)
I was so distraught, crying, wailing...couldn't believe this had happened.
After I calmed down, I re-examined how I'd been dealing with him. Everything was much more physical with him...I was always grabbing his collar, moving him physically, etc. And it just wasn't working...obviously.
So I started a whole new game plan...there was no touching unless absolutely necessary. Treats were used for moving him into other positions. Clicker/treat were used for good behavior. I prevented behaviors I didn't like from happening by keeping him away at dinner time, etc. Body blocks were used rather than forcing him to do stuff. Hands off, rewards for everything good...set him up for rewards rather than failure and punishment. Leash on a buckle collar in case I needed to move him without touching (no collar corrections, just picking up the leash and saying "let's go!" Everything was motivating for him...I let him think that he was making all the good stuff happen.
Along with this, was a lot of positive reinforcement for handling...click/treat for moving body parts, collar grabs, anything that set him off.
I think he can be worked with...but it's up to you whether you're in it for the long haul or not. But I'd say, start a hands-off, no physical confrontation style right NOW....for your safety if nothing else
"I don't have any idea if my dogs respect me or not, but they're greedy and I have their stuff." -- Patty Ruzzo
"Dogs don't want to control people. They want to control their own lives." --John Bradshaw