Generally speaking, children’s teeth can be formed before they are born.
You will see your child’s first primary teeth erupt in as early as 4 months. Depending on the child, all 20 baby teeth are typically grown in by the time they are 3 years old.
Here is an approximate order of when primary teeth erupt:
Around 6 years old, primary teeth start to prepare for their replacement by permanent teeth, which typically start with their first molars. Third molars (or “wisdom teeth”) typically erupt during mid to late adolescence. The process of growing permanent teeth continues until they are around 21 years old.