When I was a kid, checking orchards with my dad a dog charged us. Dad reached out and caught the bottom of the mutt's jaw in his right hand with his middle finger and thumb sticking inside. When you hold a dog's mouth like that, they cannot close their mouth. I saw Dad do that many times, but, have never felt like I've had the speed to pull it off myself.
Had mandatory training at work once, where we were instructed, if menaced by a dog to either, Stand like a tree, or huddle like a rock. The idea being the dog would sniff you, and at worst, pee on you before leaving. I'm pretty sure that woman had never seen an angry dog in her life.