Possible Impact of Mylohyoid Muscle Architecture on Reduced Hyolaryngeal Elevation

Abstract

One of the most important problems in swallowing function is the risk of inadequate airway closure and aspiration. Insufficient hyolaryngeal elevation during swallowing is one of the reasons for this risk. Suprahyoid (SH) muscles are fundamental structures responsible for hyolaryngeal elevation. Inadequate activation of SH muscles causes insufficient and reduced hyolaryngeal elevation. Reduced hyolaryngeal elevation causes insufficient opening of the upper esophageal sphincter (UES), leading an increase in the amount of pharyngeal residue and a risk of aspiration. Superior hyolaryngeal excursion during swallowing contributes to airway protection and prevention of aspiration. Anterior hyolaryngeal excursion is related to the UES opening and its crucial for the safe transition of bolus to esophagus without aspiration. Our study hypothesized that the long sarcomere length of mylohyoid muscle could be a contributing or responsible factor to the reduction in the hyolaryngeal elevation. There is no study on the pathophysiology on sarcomere properties of reduced hyolaryngeal elevation. Reduced hyolaryngeal elevation emerges as a symptom that reveals the cause of aspiration. Explaining the potential mechanism of reduction in hyolaryngeal elevation may contribute to the development of new treatment approaches based on architectural features in dysphagia rehabilitation practices. Furthermore, based on our hypothesis, we recommend new therapy approaches that may contribute to reducing the hyolaryngeal elevation.