The ideal starting time of treatment varies greatly depending on whether or not the three-dimensional positional relationship between the upper and lower jaws is harmonized lower jaw Compared to the upper jaw that protrudes forward (protruding teeth) Compared to the upper jaw, the lower jaw protrudes forward (receiving hole) , and there is a gap between the upper and lower teeth, etc. When the upper and lower jaws grow from permanent teeth to permanent teeth in order to adjust the amount of growth of the upper and lower jaws and to harmonize the positional relationship between the upper and lower jaws > The time when the teeth have grown to permanent teeth because there is no need to adjust the amount of jaw growth