J.B.
Ask your dentist. I had this but it wasn't treated until I was a teenager so after orthodontics, I needed surgery anyway. Two of my sons (5 & 7) inherited the same facial structure. The 7 year old will start orthodontics within a year to expand the top palate and pull the bottom jaw back underneath the top jaw. My 5 year old will also start sometime at around age 7 or 8. The current thinking is that when corrected while the plates are still growing, it's more likely to correct the problem and minimizes the chances of needing surgery later.