There are many reasons for the symptoms of oral anaerobic infections, such as dental caries, periodontitis, pulp necrosis and so on. 1. Dental caries: Dental caries will form cavities, which will lead to food debris embedded in them, and after bacterial metabolism, there is an obvious odor, which will lead to oral anaerobic infection symptoms. 2. Periodontitis: If the soft tissues around the teeth form periodontal pockets, the anaerobic bacteria in the periodontal pockets will appear inflammatory secretions, which will lead to the symptoms of oral anaerobic infections, accompanied by periodontal redness, swelling and bleeding. 3. Pulp necrosis: pulp necrosis can also lead to symptoms of oral anaerobic infections, pulp necrosis bacteria penetrate out of the apical foramen will make the surrounding red and swollen, and in severe cases, it can lead to maxillofacial swelling, pain and other phenomena. There are many reasons for the symptoms of oral anaerobic infections, and it is recommended to consult a doctor in time after the symptoms appear, improve the systematic examination and make a clear diagnosis, and then give standardized treatment, do not ignore the symptoms and take them lightly.