title: Gender difference in unstimulated whole saliva flow rate and salivary gland sizes.
abstract: OBJECTIVE
  A gender difference in the unstimulated whole saliva flow rate (UWSFR) may be due to a difference in the sizes of the salivary glands. In this study, we investigated the relationships among the UWSFR, gland sizes and body sizes of healthy young adult males and females.
  
  
  METHODS
  Unstimulated whole saliva was collected for 5 min by the spitting method in 50 healthy young adults, and the flow rate of the saliva was measured. Heights and weights were measured, and body mass indices (BMI) were calculated. The sizes of the salivary glands were measured by use of a magnetic resonance imaging technique.
  
  
  RESULTS
  Parotid and submandibular gland sizes and flow rates in females were significantly smaller than those in males, as were also the weights, heights and BMI. In both males and females, there were significant positive correlations between gland sizes and the flow rates, weights and BMI. The variations of the flow rates were reduced by standardizing them with gland sizes, weights and BMI.
  
  
  CONCLUSIONS
  These results suggest that the lower UWSFR in females as compared with males is due to the smaller gland sizes due to the smaller body sizes.
authors.affiliation: Department of Biosciences, Kyushu Dental College, 2-6-1 Manazuru, Kokurakitaku, Kitakyushu, Fukuoka 803-8580, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Inoue
authors.forename: K
authors.initials: K
authors.lastname: Ono
authors.forename: W
authors.initials: W
authors.lastname: Masuda
authors.forename: Y
authors.initials: Y
authors.lastname: Morimoto
authors.forename: T
authors.initials: T
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Yokota
authors.forename: K
authors.initials: K
authors.lastname: Inenaga
mesh_terms: D000328:Adult; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D004958:Estradiol / Q000032:analysis; D005260:Female; D006801:Humans; D008297:Male; D008597:Menstrual Cycle / Q000502:physiology; D010306:Parotid Gland / Q000033:anatomy & histology / Q000502:physiology; D011374:Progesterone / Q000032:analysis; D012463:Saliva / Q000737:chemistry; D012469:Salivary Glands / Q000033:anatomy & histology* / Q000502:physiology; D012472:Salivation / Q000502:physiology*; D012737:Sex Factors; D013363:Submandibular Gland / Q000033:anatomy & histology / Q000502:physiology
chemical_list: D011374:Progesterone; D004958:Estradiol