Oral Dryness among Japanese Youth: Development of a Japanese Questionnaire on Oral Dryness and the Impact of Daily Life on It

The purpose of this study was to develop a Japanese questionnaire for subjective oral dryness and revealfactors associated with xerostomia among Japanese youth. A sample of 237 male and 144 female Japanese students (mean age: 20.8 years) was selected. The validity of the questionnaire was assessed through factor analysis, while its reliability and internal consistency were assessed with Cronbachʼs alpha. The impact of health, daily life,food intake, and oraldryness on xerostomia was assessed. To this end, subjects responded to questions on oral dryness, health, daily life, and food intake; unstimulated saliva was also collected from the subjects. Unstimulated salivary flow rate ranged from 0.02 to 1.8 ml/min (mean: 0.32ml/min.). Factor analysis revealed that the questionnaire comprised 12 items making up four factors, namely,"at swallowing the food particle," "oraldryness during mastication," "dryness of the lips or facial surface," and "dryness at night." All factors had a Cronbachʼs alpha of 0.6 or more. In addition, subjects with an unbalanced diet had a threefold susceptibility to xerostomia. The questionnaire is deemed a valid and reliable measure of subjective oral dryness among Japanese youth. By using this questionnaire, the relationship between xerostomia and a self-reported unbalanced diet was suggested.