Halitosis is the bad taste of the mouth, there is no effective way to improve the bad taste of the mouth, the bad taste of the mouth may be caused by periodontitis, wisdom tooth pericoronitis and other diseases, the treatment is periodontal treatment and incision and drainage, as follows. 1. Periodontitis: some Gram-negative periodontitis pathogenic bacteria have odor producing function, which can lead to oral odor, through the perfect periodontal treatment, including scaling, subgingival scraping and root planing, periodontal surgery, etc., to control periodontal inflammation and alleviate oral odor. 2. Wisdom tooth pericoronitis: due to oral impurity, thickening of the tongue, oral odor and other symptoms, the treatment is repeated rinsing of the gingival pocket in the acute stage, to be incised and drained after the formation of pus, and removal of the wisdom teeth after the acute inflammation subsides. Mouth odor may have other reasons, it is recommended to go to the hospital in time to receive professional treatment as soon as possible.