What is the result of a small anterior fontanelle?

It's normal. A small anterior fontanel is an otherwise healthy baby is generally no problem at all -- and the same goes for large anterior fontanels. They do sometimes go along with other medical conditions, but those conditions are generally obvious enough that parents would generally already be aware of them. Usually a small fontanel is just normal.
Small fontannelle. The size of the fontanelle changes as a child goes throughout the first 12-18 months. The small size of the fontanelle is not significant if the head is growing at a normal rate and normal shape. Concern qould be if the head size is not growing at a normal rate or does not have a normal shape.