Masticatory ability is associated with bone mineral density in young women with normal bone mineral density

Abstract

We examined the relationship between masticatory ability and bone mineral density (BMD) and the role of muscle strength in those relationships in 156 female university students. Masticatory ability was assessed using a color-changeable chewing gum method. The BMD of the calcaneus was measured using quantitative ultrasonography and represented by a T-score, the standard deviation (SD) from the mean BMD of young adults. Body composition, grip strength, physical activity level, and daily nutrient intake were also assessed. Osteopenia, defined as the T-score < ‒1.0 SD, was present in 43 participants (27.6%). There was no significant relationship between masticatory ability (ΔE) and T-score in all participants. In participants with normal BMD (T-score ≧ ‒1.0 SD: the normal BMD group), masticatory ability significantly correlated to BMD (r = 0.289, p = 0.002). There was significant correlation between ΔE and grip strength neither in all participants nor in either group, although the grip strength in the normal BMD group was greater than that in the participants with osteopenia (the low BMD group) (p = 0.039). Physical activity level was positively correlated to the total daily energy intake (r = 0.193, p = 0.041) only in the normal BMD group. The present results suggest that masticatory ability is associated with BMD in young females with normal BMD, but the role of muscle strength in those relationships remains unclear. Meanwhile, there was no relationship between masticatory ability and BMD in young individuals with lower BMD.