Color Scale of Masticatory Performance Evaluating Gum and Web-based System

Methods: Ten participants were natural dentition without temporomandibular disorder and salivary dysfunction (26 to 30 years, mean age 27.7 years). They chewed the gum (Masticatory Performance Evaluating Gum XYLITOL, Lotte, Tokyo, Japan) for 20, 40, 60, 80, 100, 120, 160, and 200 strokes (performed 5 times respectively). The color was measured in the CIELAB color space using a colorimeter (CR-13, KONICA MINOLTA, Tokyo, Japan). Color differences between two colors before and after chewing (ΔE) were calculated. A liner regression analyses of ΔE and L*a*b* were respectively conducted, and the color scale was developed using the regression expressions. To assess the validity, an evaluation method using the color scale by 6 patients without color blindness (68 to 84 years, mean age 74.0 years) was compared with the conventional method using the colorimeter, and the Spearman’s rank correlation coefficient was calculated. The JMP 8 (SAS Institute Inc., Cary, NC, USA) was used for all statistical analyses. The Web-based system for the self-evaluation of masticatory performance using the color scale was constructed and accessed by the 15 participants (19 to 70 years, mean age 37.1 years) for verification of the operation.

Results: A significant liner relationship was found between ΔE and L*a*b* (P<0.001, R²=0.92, 0.99, 0.98). The Spearman’s rank correlation coefficient between the method using color scale and colorimeter was significant (P<0.001, r_s=0.96). Accessing the Web-based system, 15 participants could register, enter their own results with the color scale, and obtain feedback without trouble.

Conclusions: These results suggest that the patients probably evaluate their masticatory performance by themselves using the color scale and web-based system.