In comparison with Eichner’s A1 category, the level of the masticatory ability was impaired in subjects in both Eichner’s B and C categories. The level of masticatory ability was significantly associated with the category of the Eichner’s index (one-factor ANOVA; p < 0.01). Pairwise comparisons showed significant differences between the following categories: A1 and B2, A1 and B3, A1 and B4, A1 and C2, and A1 and C3 (Fig 4).