The most likely reason is due to poor oral hygiene environment, due to long-term no serious brushing, rinsing, and no regular hospital dental cleaning people, such people will have a lot of food residues, soft scales, bacteria, these dirty things in the mouth for a long time will be spontaneous corruption, production of odor, resulting in sleep 2.If there is dental disease in the mouth, such as multiple tooth decay in the mouth, because the cavity is a place to hide dirt, the food residue in the cavity will also be corrupted and produce odor, which will also cause the stink of drooling in bed. 3.If there is wisdom tooth pericoronitis, periodontitis, periodontal abscess or large mucosal ulcers in the mouth, due to the increase in the number of pathogenic factors in the mouth, the increase in inflammatory The increase in exudate will also cause the phenomenon of drooling during sleep is very smelly.