Ultrasonographic Measurement of Thickness of the Thyrohyoid Muscle: A Pilot Study

OBJECTIVE: To evaluate the normal thickness of the thyrohyoid muscle, which is one of the key muscles related to swallowing, by ultrasonography. METHODS: The thickness of the left and right thyrohyoid muscles was measured in normal male and female adults ranging in age from 20 to 79 years by ultrasonography. The groups were classified according to age as follows: subjects ranging in age from 20 to 39 years were classified into group A, subjects ranging in age from 40 to 59 years were classified into group B, and subjects ranging in age from 60 to 79 years were classified into group C. The measurement level was the line that joins the upper tip of the superior thyroid notch and the oblique line of the thyroid cartilage. Also, a correlation with the thyrohyoid muscle was investigated by collecting information regarding height, weight, body mass index (BMI), age, and gender of subjects in the healthy group. RESULTS: The number of subjects in each group was as follows: group A (n=82), group B (n=62), and group C (n=60). Also, the thicknesses of the left and right muscles were 2.72±0.65 mm and 2.87±0.76 mm in group A, 2.83±0.61 mm and 2.93±0.67 mm in group B, and 2.59±054 mm and 2.73±0.55 mm in group C, respectively. Thyrohyoid muscle had a correlation with height, weight, and BMI. The thickness of the left and right thyrohyoid muscles was greater in male subjects than in female subjects and the right side muscle was thicker than the left side muscle. CONCLUSION: The average thickness of the left and right thyrohyoid muscles was 3.20±0.54 mm in male subjects and 2.34±0.37 mm in female subjects. The thickness of the thyrohyoid muscle was positively correlated with height, weight, and BMI, and the thyrohyoid muscle was thicker in male subjects than in female subjects and the right side muscle was thicker than the left side muscle.

The Effects of the VFSS Timing After Nasogastric Tube Removal on Swallowing Function of the Patients With Dysphagia

OBJECTIVE: To evaluate the effects of the videofluoroscopic swallowing study (VFSS) timing after the nasogastric tube (NGT) removal on swallowing function of the patients with dysphagia. METHODS: This study was conducted on 40 NGT-fed patients with dysphagia. To assess the patients' swallowing function, VFSS was performed twice using a 5-mL 35% diluted barium solution. For the initial examination, VFSS was performed immediately after the NGT removal (VFSS 1). For the second examination, VFSS was performed five hours after the NGT removal (VFSS 2). We used the functional dysphagia scale (FDS) to assess swallowing function. In the FDS, a significant difference in the four items in the oral phase, seven items in the pharyngeal phase, and total scores were assessed (p<0.05). We also used modified penetration-aspiration scale (mPAS) to compare the two examinations (p<0.05). RESULTS: A paired t-test was performed to confirm the statistical significance of the two examinations (p<0.05). The overall swallowing function was assessed as better in VFSS 2 than in VFSS 1. In the FDS, significant differences in the residue in valleculae (p=0.002), the residue in pyriform sinuses (p=0.001), the coating of pharyngeal wall after swallow (p=0.001), and the total scores (p<0.001) were found between the two examinations. Also, in the mPAS that assessed the degree of penetration-aspiration, a significant difference was found between the two examinations (p<0.001). CONCLUSION: The results of this study confirmed that the timing of the VFSS after the NGT removal affects the swallowing function. Thus, to accurately assess the swallowing function, VFSS must be performed in NGT-fed patients after they have rested for a certain period following the removal of their NGT.