Association between tongue muscle strength and masticatory muscle strength

<jats:title>Summary</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>The tongue is responsible for compressing food against the palate and squeezing it into the pharynx during the oral preparatory phase of swallowing. Tongue pressure (<jats:styled-content style="fixed-case">TP</jats:styled-content>), an indicator of tongue muscle strength, has been observed to decline with age; maximum occlusal force (<jats:styled-content style="fixed-case">MOF</jats:styled-content>), an indicator of chewing ability, is correlated with <jats:styled-content style="fixed-case">TP</jats:styled-content>. However, no study has investigated the relationship between <jats:styled-content style="fixed-case">TP</jats:styled-content> and <jats:styled-content style="fixed-case">MOF</jats:styled-content>.</jats:p></jats:sec><jats:sec><jats:title>Objective</jats:title><jats:p>To investigate the correlation between <jats:styled-content style="fixed-case">TP</jats:styled-content> and <jats:styled-content style="fixed-case">MOF</jats:styled-content> according to age in healthy individuals.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>We retrospectively collected handgrip strength (<jats:styled-content style="fixed-case">HGS</jats:styled-content>), body mass index (<jats:styled-content style="fixed-case">BMI</jats:styled-content>), <jats:styled-content style="fixed-case">TP</jats:styled-content>,<jats:styled-content style="fixed-case"> MOF</jats:styled-content> and tooth loss data for 785 healthy participants (305 men, 480 women). All subjects had either unilateral or bilateral occlusal support, regardless of the presence of dentures or natural teeth. The participants were divided into two groups: an adult (20s‐50s, n = 497) group and an elderly (60s‐80s, n = 288) group. Multivariate linear regression analysis was performed to determine significant independent variables associated with <jats:styled-content style="fixed-case">TP</jats:styled-content> in both groups.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Multivariate analysis revealed that <jats:styled-content style="fixed-case">TP</jats:styled-content> was significantly associated with age (<jats:italic>β</jats:italic> = −0.153), <jats:styled-content style="fixed-case">BMI</jats:styled-content> (<jats:italic>β</jats:italic> = 0.205), <jats:styled-content style="fixed-case">HGS</jats:styled-content> (<jats:italic>β</jats:italic> = 0.298) and <jats:styled-content style="fixed-case">MOF</jats:styled-content> (<jats:italic>β</jats:italic> = 0.239) in the adult group (all <jats:italic>P</jats:italic> < 0.001) and with age (<jats:italic>β</jats:italic> = −0.266, <jats:italic>P</jats:italic> < 0.001), <jats:styled-content style="fixed-case">BMI</jats:styled-content> (<jats:italic>β</jats:italic> = 0.160, <jats:italic>P</jats:italic> = 0.005), <jats:styled-content style="fixed-case">MOF</jats:styled-content> (<jats:italic>β</jats:italic> = 0.217, <jats:italic>P</jats:italic> = 0.001) and tooth loss (<jats:italic>β</jats:italic> = 0.156, <jats:italic>P</jats:italic> = 0.011) in the elderly group.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>As age and <jats:styled-content style="fixed-case">MOF</jats:styled-content> are each associated with <jats:styled-content style="fixed-case">TP</jats:styled-content> in both elderly and adult patients, age‐related <jats:styled-content style="fixed-case">TP</jats:styled-content> decline can be prevented with routine lingual exercises, even before the onset of old age. Additionally, <jats:styled-content style="fixed-case">MOF</jats:styled-content> deterioration may indicate a decline in <jats:styled-content style="fixed-case">TP</jats:styled-content> for elderly.</jats:p></jats:sec>