Hi
No need to worry.
Every tooth has different eruption time and as you have mentioned he is just 8 the teeth can erupt any time between 8-9 years or sometimes 9.5.
In case they don’t come out even then you can visit a dentist and not every child has the same growth pattern so give it time.
Next Steps
If at all you want consult a dentist online/offline
Health Tips
Just maintain a good oral hygiene