Diagnostic performance of labial minor salivary gland flow measurement for assessment of xerostomia.
OBJECTIVE
Minor salivary gland flow rate (MF) has been proposed as a key feature of xerostomia (subjective feeling of dry mouth). To assess its diagnostic performance, MF was compared in xerostomia and control subjects.


METHODS
Sixty-six subjects with xerostomia and 30 controls were enrolled. MF was measured in the lower labial mucosa using the iodine-starch filter paper method. Stimulated whole salivary flow rates were also measured using the gum test (stimulated-WF).


RESULTS
Both labial-MF and stimulated-WF were significantly lower in xerostomia subjects than in controls. There was a positive correlation between labial-MF and stimulated-WF in control but not xerostomia subjects. In xerostomia subjects compared to controls, there was a significantly larger reduction in labial-MF than in stimulated-WF. Xerostomia was most accurately diagnosed using a labial-MF cutoff value of 0.25 μL/cm(2)/min. The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy at this cutoff value were 1.00, 0.87, 0.93, 1.00, and 0.96, respectively. Compared to respective values of 0.64, 1.00, 1.00, 0.56, and 0.75 for stimulated-WF at the traditional cutoff of 1.0 mL/min, these data indicate the higher sensitivity, negative predictive value, and diagnostic accuracy of labial-MF.


CONCLUSIONS
Xerostomia was more strongly related to reduction of labial-MF than to that of stimulated-WF. Xerostomia was most likely triggered at a labial-MF cut-off value of 0.25 μL/cm(2)/min based on results from the iodine-starch method.
Division of Oral Diagnosis, Department of Oral Medicine and Surgery, Tohoku University Graduate School of Dentistry, Seiryo-machi 4-1, Aoba-ku, Sendai 980-8575, Japan.
Shizuko
S
Satoh-Kuriwada
Masahiro
M
Iikubo
Noriaki
N
Shoji
Maya
M
Sakamoto
Takashi
T
Sasano
D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012470:Salivary Glands, Minor / Q000378:metabolism*; D012472:Salivation / Q000502:physiology*; D012636:Secretory Rate / Q000502:physiology; D012680:Sensitivity and Specificity; D014987:Xerostomia / Q000175:diagnosis* / Q000503:physiopathology*