Pathological Bucales are the causes of Halitosis.

Poor hygiene, lack of brushing or poor brushing.
     * For caries
     * Periodontal disease (there are tartar, plaque accumulation)
     * Gingivitis (inflammation of the gums)
     * Gangrene pulp (characterized by an extremely unpleasant odor caused by germs that invade the dental pulp).
     * Prosthetics poorly sanitized.
     * Smoking (which decreases the secretion salivary)
     * Xerostomia.