S.O.
I still have several baby teeth and I am 46. I never developed all my adult teeth and I am grateful my baby teeth have lasted this long. You can ask the dentist to check (x-ray) and make sure all his adult teeth have develop. If he has all his adult teeth I would not worry. Both my daughters adult teeth came in later. I was once told by a dentist if they get their baby teeth later they will also get their adult teeth later.