For the most part, this article reflects AuntGoo's experience as an Occupational Therapist treating autistic kids, birth through high school. She works primarily in the local school systems, with all manner of special needs kids, but initially worked in a big city hospital setting with severely autistic kids. From 2001 through 2005 she operated a preschool for special need--primarily autism--birth to four year olds, with the idea that early intervention would help them when they entered the public school system. When she opened the preschool, we had a rescue dog--a ten year old, toothless chihuahua, who was particularly empathetic to people who were sick or felt "out of sorts." AuntGoo brought Dusty to the preschool one day, for "show and tell." He would sidle right up the kids who were stressed by the activities, and sit calmly beside them. For the most part these kids picked up on his calm, and calmed down, too.
Were there exceptions? Sure: some of the kids took a bit to warm up to him and some were too rough with him, but Dusty ended up as a regular fixture there, because he was an asset, even without any formal training (that we knew of) on his part.
Every dog is different, every human is different. There are possibilities to this type of treatment.
On a side note, it was because ALL of Dusty's teeth were gone, that AuntGoo felt safe bringing him to the preschool. He knew to move away if someone was too rough, but when he couldn't escape, he'd growl and snap like any other dog. A couple of the kids learned to be nice and gentle, by being too rough and getting "gummed" for it. From my own experience trying to trim his nails, I can tell you that even when you know a dog has no teeth, if he snaps at you, you're going to jerk your hand away.