Teeth soft and no force may be wedge-shaped chipped teeth, cryptocleidosis or periodontitis, the specific need to go to the hospital to check the teeth and periodontal conditions to determine the cause of the disease. 1. Wedge-shaped chipped teeth: teeth feel soft and weak, may be the dentin exposure after wedge-shaped chipped teeth, upper and lower biting teeth in contact with food, hot and cold or sweet and sour stimulation triggered by the pulp of the reactive pain, there will be soreness and biting weakness phenomenon. 2. Cracked teeth: When the teeth like to eat hard objects or by external impact caused by cracked teeth, the teeth of the upper and lower occlusion will appear in specific parts of the soreness and can not bite the symptoms. 3. Periodontitis: Periodontitis attaches to the loss of alveolar bone resorption, which can lead to loosening of the teeth, exposure of the tooth roots, biting pain or soreness, and inability to chew food. When any dental discomfort occurs, it is recommended to seek medical examination as soon as possible to avoid interfering with eating.