It is shown that volatile short-chain fatty acids (propionate, butyrate and acetate) of bacterial and tissue origin are important factors of pathogenesis of oral tissue inflammation. A comparative biochemical study using chromato-mass-spectrometry, gas adsorptive and gas-liquid chromatography of oral media in healthy subjects has discovered that in gingivitis and parodontitis these media contain higher concentrations of short-chain fatty acids and lower ones of relevant aldehydes in intensification of the inflammatory process. The ratios of acetate/acetaldehyde, propionate/acrolein, butyrate/butyraldehyde increase considerably with intensification of parodontic inflammation making these values suitable for assessment of inflammation severity.