Inward tilting of teeth can be corrected by orthodontic treatment. The reason for inward tilting is that the teeth are crowded in the mouth, and the degree of crowding can be evaluated by taking surface tomography films and making certain measurements. If a few unwanted teeth need to be removed, it is better to remove them routinely to leave enough space for the rest of the teeth before orthodontic treatment. The orthodontic treatment is completed by aligning the teeth as much as possible, then closing the gap between the teeth, and finally adjusting the bite slightly so that the bite is in a more ideal jaw-building state.