Low salivary flow and volatile sulfur compounds in mouth air

Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Jul;96(1):38-41. doi: 10.1016/s1079-2104(03)00162-8.


Objective: The purpose of this study was to determine whether a reduction of salivary flow would influence the production of methylmercaptan (CH(3)SH) and hydrogen sulfide (H(2)S), which are volatile sulfur compounds (VSCs) known to cause oral malodor.

Study design: The VSCs in mouth air were measured by means of gas chromatography. Spitting and masticatory (stimulated) methods were used to determine the salivary flow rates of 174 patients.

Results: There was no significant correlation between the level of VSCs and salivary flow rate. However, subjects with extremely low resting salivary flow rates had significantly higher CH(3)SH and H(2)S concentrations and tongue-coating scores than those with higher resting salivary flow rates. Moreover, logistic analyses revealed that extremely low resting salivary flow, the increase in tongue coating, and a probing pocket depth greater than 4 mm were strong explanatory factors for the generation of VSCs, which could have caused oral malodor.

Conclusions: These findings suggested that an extreme reduction in resting saliva influenced the generation of CH(3)SH and H(2)S in mouth air.

MeSH terms

  • Adult
  • Breath Tests
  • Female
  • Halitosis / etiology*
  • Halitosis / metabolism
  • Humans
  • Hydrogen Sulfide / metabolism*
  • Logistic Models
  • Male
  • Middle Aged
  • Odds Ratio
  • Periodontal Index
  • Saliva / metabolism*
  • Secretory Rate
  • Statistics, Nonparametric
  • Sulfhydryl Compounds / metabolism*
  • Xerostomia / complications
  • Xerostomia / metabolism


  • Sulfhydryl Compounds
  • methylmercaptan
  • Hydrogen Sulfide