Each tooth contains different nerves, which are distributed like the veins of a leaf, but basically for the front teeth there is one nerve. There are variants with two nerves, but the probability is very low. For bicuspid teeth, they usually contain a single root or two roots or a mixed type, so the treatment of bicuspid teeth is more complicated than that of anterior teeth. For the posterior molars, there are usually three to four nerves, and even five nerves in some cases with large variants, or two nerves in some cases, so the nerve situation varies from person to person. After treatment, the nerve must be completely removed, this process is actually very complex, basically can be considered the most technically difficult in dentistry treatment, so it is recommended that patients should not blindly choose small clinics when treating teeth, or go to regular clinics and hospitals for treatment.