Age-related declines in the swallowing muscle strength of men and women aged 20–89 years: A cross-sectional study on tongue pressure and jaw-opening force in 980 subjects

•Tongue pressure (TP) and jaw-opening force (JOF) decline with age.•The decrease in TP and JOF is more significant in men than women.•TP declined more steeply than did the JOF.•Different patterns exist in the age-related decline in swallowing muscle strength.•Maintained JOF in healthy elderly people might contribute to safe swallowing. Swallowing muscle strength weakens with aging. Although numerous studies have investigated tongue pressure (TP) changes with age, studies on jaw-opening force (JOF), an indicator of suprahyoid muscle strength, are lacking. We investigated differences between age-related declines in TP and JOF in a cross-sectional study of 980 healthy and independent participants (379 men, 601 women) without dysphagia. Hand grip strength (HGS), TP, and JOF were compared among decade-based age groups in multiple comparison analyses with post-hoc tests and effect size calculated. Participants were divided into adult (20 s–50 s) and elderly groups (60 s–80 s); within each group, Pearson correlations between age and muscle strength indices were evaluated. TP started to significantly decline in the 60 s and 50 s for men and women (p