Aging Decreases the Strength of Suprahyoid Muscles Involved in Swallowing Movements

Abstract

Swallowing disorders are common in the elderly, and aging is a factor that affects swallowing function. The elevation of the hyoid bone is important for swallowing and is controlled by the suprahyoid muscles. The hyoid and laryngeal elevation allows the bolus to enter the esophagus. The suprahyoid muscles, therefore, play an important role in swallowing. The effects of aging on suprahyoid muscle strength are unclear. In this study, we analyzed the effects of aging on suprahyoid muscle strength by comparing the jaw opening functions of healthy adults and elderly adults. The subjects were 150 healthy volunteers consisting of 76 adults aged < 70 years (38 men and 38 women; mean age, 48.8 ± 13.8 years; range, 23-69) and 74 elderly adults aged > 70 years (37 men and 37 women; mean age, 78.1 ± 4.8 years; range, 70-92). The jaw opening force (JOF) was measured with a jaw opening sthenometer and compared between the healthy adult and elderly groups. The mean JOF of healthy adults was about 10 kg in men and about 6 kg in women, which was significantly greater than the mean JOF of the healthy elderly subjects (about 7 kg in men and about 4 kg in women). The JOF of the men was significantly greater than that of the women in the healthy adult and elderly groups. We thus propose that aging decreases the strength of suprahyoid muscles in healthy adults. The swallowing function may decrease even in healthy adults, aged over 70 years.

Relationship between jaw opening force and hyoid bone dynamics in healthy elderly subjects

“…Lowering of the larynx and hyoid is believed to result from age-related atrophy of the suprahyoid muscle fibers, reduced tension, and loosening of the ligaments 14. On the other hand, a previous study reported that when comparing jaw opening force in healthy individuals, the strength of the suprahyoid muscles was lower in those aged ≥70 years than in those aged <70 years 9. Greater jaw opening force leads to higher hyoid position at rest because when measuring jaw opening force, the muscles and joints are in a fixated position.…”

“…Jaw opening force is correlated with grip strength, which is an indicator of systemic muscle strength 8. As compared with healthy adults, healthy elderly individuals have significantly reduced jaw opening force 9. Moreover, reduced jaw opening force has been suggested to increase the risk of aspiration and pharyngeal residue 10.…”

Recurrent Laryngeal Nerve Paralysis after Esophagectomy: Respiratory Complications and Role of Nerve Reconstruction

“…The operation time is usually associated with the extent of tumor progression, and surgeons may become fatigued as the operation time lengthens. The strength of tissues, possibly including nerves, in elderly patients is thought to be lower than that of younger patients (Iida et al 2013). These results demonstrate that gentle and precise surgical maneuvers are absolutely essential to prevent RLNP.…”

Oculopharyngeal Muscular Dystrophy as a Paradigm for Muscle Aging

“…Most skeletal muscles are weakened during aging; however, it is unclear whether aging-associated muscle weakness is programed, concerning initially affected muscles and progression. Relevant to OPMD, dysphagia, resulting from weakness of pharyngeal muscles, and eyelid ptosis, resulting from weakness of the levator palpebrae muscle, is highly common in the elderly (Salvi et al, 2006; Fea et al, 2013; Iida et al, 2013). In contrast to the otherwise healthy population, in OPMD, symptoms start at an earlier age and seem more severe, possibly due to faster progression.…”