Well, this is a textbook example of error. Proper flossing should look like this: Pull the floss out of the floss box and take an arm's length of floss (about 45 cm). Wrap the dental floss around the second knuckle of the index fingers of both hands, and wrap it two or three times to fix the dental floss. Do not wrap all the dental floss around the index finger, which will affect blood circulation.
When flossing the front teeth area, use the thumb of one hand and the index finger of the other hand to tautly floss the two fingernails about 1 cm apart. Put the dental floss at the junction of the gums and the teeth, with the index finger inside the mouth and the thumb outside the mouth.
When cleaning the posterior teeth area, use the index fingers of both hands instead, and straighten the fingers to reach the gap between the posterior teeth. The left and right adjacent surfaces of the upper and lower scraping gaps. Most people only use dental floss to remove food residues, but do not implement the action of "scraping" the surface of the teeth. The invisible plaque still accumulates between the teeth, and the cleaning effect is greatly reduced.