Is the glass half full or half empty?
Witzel
M A
MA
D002972:Cleft Palate; D005145:Face / Q000002:abnormalities*; D049673:History, 20th Century; D006801:Humans; D012886:Skull / Q000002:abnormalities*; D012953:Societies, Dental / Q000266:history / Q000639:trends*; D014481:United States