At my child (9 months) the first tooth in top has grown. Prompt please...

[Elena]

At my child (9 months) the first tooth in top has grown. Prompt please it normally, what in 9 months only one tooth? And in all books I read, that the first tooth necessarily should be bottom. Thanks.

[Chernorutskaja E.I.]

Has appeared pozdnovato, but can be not necessarily bottom. Though, more often, prorezyvanie other groups of a teeth and