Device for measuring dryness of the oral mucosa. A preliminary report.

Following a survey of various methods used to register oral mucosal dryness--xerostomia--a new device, measuring surface slide friction, has been developed. An instrument is devised to register the twisting force as well as the force at right angle to the surface. Calculations from these parameters give standardized expressions for friction between the probe of the instrument and the oral mucosa. By using methylscopolamine, 3 students were tested for dryness in the mouth. The instrument showed a peak of increased friction after about 60 min. The reliability was tested by using various water solutions of a macromolecule as interphase between the instrument and the steel plate. These preliminary tests indicated that the instrument showed values of good validity and reliability. It should be further developed for registering oral mucosal dryness in clinical settings.