Eleven months before the baby teeth, when the twelve months to grow the top two front teeth, but the left one first exposed to little yellow, and now has grown together, and a little yellow.
Of course not tetracycline stained teeth, and I suggest you look into dentistry, there really such a thing, but for many reasons, pigmentation, and some related to the development and early, you did not say how much your child, it is difficult to judge reasons.
