Dental crowding can be corrected by extracting or not extracting the teeth, the details are as follows: 1, the degree of crowding in the teeth within 4mm belongs to the mild crowding, can be through the expansion of the dental arch, push the grinding teeth backward and the neighboring surfaces to glaze three methods of corrective treatment; 2, the degree of crowding in the teeth in the teeth in the more than 4 mm more than 8 mm less than the degree of crowding is moderate crowding, you need to be extracted by way of orthodontic treatment; 3, crowding in the teeth in the teeth in the more than 8 mm belongs to the serious crowding, must be extracted by way of orthodontic treatment.