Teeth erupt in a certain order, not all together. The first teeth to erupt are the teeth in the middle of the lower jaw, or what we call the mandibular milk incisors. Then the maxillary central incisors begin to erupt gradually, from the center to the sides. However, this time is not constant, some children may be relatively early, some may be relatively late, if the difference is not very big, we consider it normal. Also, clinically, some children may have teeth that appear at birth, which we call birth teeth. There are several cases of birth teeth, if they are very strong normal erupted mandibular incisors, they can be retained, but some of them are degenerated epithelial beads or horse teeth, which do not need special treatment and most of them will fall out automatically.