When buying a soft-bristled toothbrush, first look at the size of the brush head. Many people who travel or live in Japan will notice that the toothbrushes provided by hotels or sold in supermarkets are one-third to one-half smaller than those commonly used in China. As a specialist, experts also tend to recommend to readers a toothbrush with a smaller brush head, and a smaller toothbrush for children. This is because the space in the posterior teeth area of the oral cavity is small, and it is difficult for the large brush head toothbrush to enter the posterior molar area, and this area will become a dead end. When dentists treat patients, they always find that the lower the teeth, the worse the cleanliness, and the amount of soft dirt, plaque, and calculus is more than in other areas. The toothbrush of the brush head can rotate flexibly in the oral cavity, can reach all parts of the teeth, and it is not easy to leave a hygienic dead corner. https://www.samemater.com/toothbrush/soft-toothbrush/high-density-flat-extra-soft-bristles-adult.html