Screening for a Decreased Masticatory Function by a Color-changeable Chewing Gum Test in Patients with Metabolic Disease.

Objective This study aimed to reveal the screening performance of a color-changeable chewing gum test for a decreased masticatory function in the assessment of oral hypofunction in patients with metabolic diseases. Methods We analyzed 1,000 patients with metabolic diseases, including diabetes, dyslipidemia, hypertension, and hyperuricemia. A decreased masticatory function was diagnosed by a gummy jelly test. Patients were asked to chew a test gum, which changed from green to red by thorough mastication, 60 times for 1 minute. The color change was visually evaluated using the color scale, from 1 (green-dominant) to 10 points (red-dominant), and was colorimetrically quantified as delta E in the L*a*b* color space. The screening performance for a decreased masticatory function was evaluated with the receiver operating characteristic (ROC) curve. Results Seventy-seven patients (7.7%) were diagnosed with a decreased masticatory function. The mean color scale and delta E of the gum test were 6.7±1.8 points and 42.9±6.7 units, respectively. The area under the ROC curve was 0.822 (95% confidence interval, 0.768-0.872) for the color scale and 0.838 (0.781-0.890) for delta E (p=0.41). The optimal cut-off point of the color scale was 5.5 (5.0-6.5) points, whereas that of delta E was 37.7 (35.5-38.8) units. The optimal cut-off points were not significantly different between the subgroups divided by clinical characteristics. Conclusions A color-changeable chewing gum test using the color scale as well as delta E would be a useful tool for screening patients with metabolic diseases for a decreased masticatory function in the assessment of oral hypofunction.