Age-related Changes in Geniohyoid Muscle Morphology Predict Reduced Swallowing Function

Background: Early detection and treatment to sarcopenia and presbyphagia are needed to address the problems experienced by an aging population. Objective: We aimed to clarify morphological changes in the geniohyoid (GH) muscle and associated aging-related factors, and to examine if changes in the GH muscle predict reduced swallowing function. Materials and Methods: 103 participants (57 women and 46 men, mean age 59.4 ± 19.5 years) were recruited. GH muscle cross-sectional area (CSA) and contraction velocity were measured using ultrasonography. Body height and weight, neck circumference, body mass index, remaining teeth number, occluding teeth number, tongue pressure, and jaw-opening strength were measured. Swallowing function was evaluated using the swallowing screening assessment questionnaire and by measuring swallowing sound duration. Results: GH muscle CSA significantly affected age, gender, body height and weight, neck circumference, remaining teeth number, occluding teeth number, tongue pressure, jaw-opening strength, duration of swallowing sounds, and GH muscle velocity. Covariance structure analysis showed that GH muscle CSA directly influenced swallowing sound duration. Conclusion: Morphological changes in the GH muscle are predictive of decline in swallowing function.