Yes I know you left that part out intentionally.  
75% of a an average person's intake in a fluoridated area comes from water and beverages made with that water, yet according to you:

 "that just leaves moderate and severe, neither of which is associated with optimally fluoridated water"  

How exactly did those with Moderate or Severe fluorosis avoid taking in any fluoride from their water?   It would be a strange coincidence if all of the people who have those levels of the disease were all buying bottled water or had an overpriced RO system installed in their homes.