title: Saliva viscosity as a potential risk factor for oral malodor.
abstract: OBJECTIVE
  The objective of this study was to assess whether saliva viscosity, measured by a viscometer, was a predictor of oral malodor.
  
  
  METHODS
  The subjects were 617 patients who visited an oral malodor clinic. The organoleptic test (OT) was used for diagnosis of oral malodor. An oral examination assessed the numbers of teeth present and decayed teeth as well as the presence or absence of dentures. Further, periodontal pocket depths (PD), gingival bleeding, dental plaque and tongue coating were investigated. Unstimulated saliva were collected for 5 min. Saliva viscosity was measured with a viscometer. Logistic regression analysis with oral malodor status by OT as a dependent variable was performed. Possible confounders including age, gender, number of teeth present, number of decayed teeth, number of teeth with PD ≥ 4 mm, number of teeth with bleeding on probing, presence or absence of dentures, plaque index, area of tongue coating, saliva flow rate, saliva pH and saliva viscosity were used as independent variables.
  
  
  RESULTS
  Saliva viscosity (p = 0.047) along with the number of teeth with PD ≥4 mm (p = 0.001), plaque index (p = 0.037) and area of tongue coating (p < 0.001) were significant variables for oral malodor. Subjects with a higher number of teeth with PD ≥ 4 mm (OR = 1.32), plaque index (OR = 2.13), area of tongue coating (OR = 3.17) and saliva viscosity (OR = 1.10) were more likely to have oral malodor compared to those with lower values.
  
  
  CONCLUSIONS
  The results suggested that high saliva viscosity could be a potential risk factor for oral malodor.
authors.affiliation: Department of Oral Health Promotion, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University , Tokyo , Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ueno
authors.forename: Susumu
authors.initials: S
authors.lastname: Takeuchi
authors.forename: Sachiko
authors.initials: S
authors.lastname: Takehara
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kawaguchi
mesh_terms: D000328:Adult; D004245:DMF Index; D003774:Dental Plaque Index; D003817:Dentition; D003778:Dentures; D005260:Female; D005884:Gingival Hemorrhage / Q000145:classification; D006209:Halitosis / Q000209:etiology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification; D012307:Risk Factors; D012463:Saliva / Q000737:chemistry* / Q000378:metabolism; D012636:Secretory Rate / Q000502:physiology; D012903:Smell; D014059:Tongue / Q000473:pathology; D014783:Viscosity
keywords: oral malodor; organoleptic test; saliva viscosity; viscometer