Possible causes of full mouth toothache are acute necrotizing ulcerative gingivitis, periodontal abscess, wedge-shaped defects, etc., as follows. 1. Acute necrotizing ulcerative gingivitis: it is an acute inflammation that occurs in the gums, with necrosis and bleeding of the gum tissues and obvious pain, often with a feeling of teeth propping up and swelling. 2. Periodontal abscess: periodontitis develops into advanced stage, purulent inflammation occurs in the periodontal tissues, acute pain is severe, there may be occlusal pain, percussion pain and throbbing throbbing pain. 3. Wedge-shaped defects: may lead to the exposure of dentin, causing dentin hypersensitivity, pain when subjected to hot, cold, sweet and sour or mechanical stimulation. There may be other reasons for a mouth full of toothache, it is recommended to go to the hospital in time.