Is it normal for 1 year old and 2 month baby s fontanel to close because my nephew s fontanel is already closed and is it effect tooth formation?

That is normal: The frontal fontanel is typically completely closed by 18-24 months, but often feels hard/sealed by your fingers by around 1 yr, some a bit earler, some later. During routine infant exam, docs/nurses check this and so if baby has been growing, developing normally, without concern from his doc, i believe he is well/normal. Watch him do wonderful stuffs as he grows! enjoy and good luck.

Read below: To answer your first question, there are several fontanels, and they close from two months up to two years. So yes it is normal. Development occurs in many areas in a developing baby. So if a baby is a late developer, usually most organs and systems will develop earlier. Same goes for late developers. So although one is not related to the other, you may get later tooth formation with late closure.

As long as his head: Circumference is growing along its curve on his growth chart, the "sutures, " spaces between the skull bones are still open. When a suture line closes prematurely, the head can't grow in that direction, so it changes shape. It's kind of like petals of a tulip that fold over the center of the flower, but are not fused, except the skull bones don't overlap like the petals do. See photo on wikipedia.