a,b,c in that order. In the United States I have not seen one 'on the street' in 25 years or so. In the early 1970's I wore one regularly in public. I was 15 at the time and hated it but was forced to wear it and I finally gave up fighting it and just wore it almost everywhere except school, even at my part time job. My ortho required hewadgear wear in the office so I saw many more than most but 'on the street' was a different story. I had two friends at the same ortho and they wore theirs 'as directed'. Everyone I talked to who actually wore their headgear, except for one (he did just not care),were forced to by parents and it was very easy to see if I/we had our headgear on. I think there was a lot of regional hotspots, headgear in public was uncommon but not unheard of in the 70's. In the eighties maybe less than once a year mostly in shopping malls but one girl at a professional tennis match (she was obviously hating life sitting with her parents) and a young girl at a Rolling Stones concert in LA. Since then one boy in a supermarket in the 90's. One reason given to me by an ortho assistant is 8-10 hours is the new normal. In the 1970's therte was a real push in some ares for full time wear. That did not happen but my ortho was one of those who loved the idea. The days of public displays of headgear, I think, are over in the US.