A small space between the front teeth of a 7 year old, less than 1 MM, is normal. However, if the space is greater than one millimeter or there are additional spaces between the other upper front adult teeth this can cause a problem for the next tooth in line.
Often, when the front teeth are spaced widely, the cuspids, or eye teeth, often do not have sufficient room to fit in line. They can push out forward of the other teeth, appearing as fangs. If the room for the cuspids is very limited, they can also take an alternate path and become stuck in the bone behind the front teeth. This takes considerable effort and resources to correct often including an oral surgery procedure to uncover the stuck teeth.