It could be staining from tetracyclene, if your mother took it while pregnant with you:
And another: emdentalgroup.com/db4/00350/emdentalgrou... The article below explains why this happens. My own brother has this problem: ncbi.nlm.nih.gov/pubmed/15485524 Staining is not necessarily on every tooth, or more than one or two. It just depends on what teeth were developing when the medicine was taken either by you or your mother when she was pregnant with you.My brother had staining on two of his baby teeth and two of his adult teeth.I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.