פורום רפואת שיניים לילדים

Hello, I noticed that my 4.5 years old boy has what looks like enamel loss on his upper teeth (you can see brown spots, some teeth are all brown) I saw it today for the first time and I'm a bit worried.

I shell see the dentist asap but do you know of this condition? what can it be??

Thank you, sorry for writing in English, I am in London with no Hebrew keyboard