We must attach importance to Ningde Oriental Plastic Surgery Hospital. The Ningde Oriental Plastic Surgery Hospital you mentioned gives you the following answer. 1, the lower teeth need to be pressed down, because the upper teeth cover the lower teeth too much in the vertical direction, which is normally within 1/3 of the crown of the lower teeth. The reason why the upper teeth are not stressed is that they are waiting for the lower teeth to move to a certain extent, because even if the upper teeth are stressed now, the relationship between the upper and lower teeth can not be adjusted until the lower teeth reach a certain position. This has no effect on the calibration process.