Is it common for a 8 yr old to not have lost any teeth?

Possibly: Most kids will begin to loose baby teeth by age 7-8. Some kids will be a little ahead of that schedule, and some will lag behind. If you're worried about something, have your child evaluated by your dentist. They can take an x-ray to see if their permanent teeth are developing properly.

Yes.: Every child gets teeth at their own pace. While 8 is a bit late it is not our of the range of normal. As always check with your child's dentist to make sure there are no problems though.