The relationship between oral malodor and volatile sulfur compound-producing bacteria

Halitosis can be a crippling social problem, and standard dental treatments and mouthwashes often provide only temporary relief. The mouth is home to hundreds of bacterial species that produce several fetid substances as a result of protein degradation. Volatile sulfur compound (VSC)-producing bacteria colonizing the lingual dorsum have recently been implicated in the generation of halitosis. Detection of VSCs, such as methylmercaptan and hydrogen sulfite, via organoleptic and objective methods, can aid in the identification of their source. Following comprehensive evaluation for possible causes, most halitosis in patients seen in an ENT practice can be localized to the tongue. We review methods of diagnosis and treatment of oral malodor from the overgrowth of proteolytic, anaerobic, gram-negative bacteria on the crevices of the lingual dorsum. Bacteriologic analysis of biofilm and scraped specimens obtained from the lingual dorsum and other oral sites, primarily gingival pockets and tonsillar crypts, can identify VSC-producing bacteria. Porphyromonas, Prevotella, Actinobacillus, and Fusobacterium species are the most common organisms identified. Halitosis is an oral phenomenon, with almost no cases originating distal to the tonsils. Halitosis arising from the lingual dorsum secondary to overpopulated VSC-producing bacteria can be successfully managed with a combination of mechanical cleansing using tongue brushes or scrapes and chemical solutions containing essential oils, zinc chloride, and cetylpyridinium chloride.