Abstract
Objective: This study evaluated the effect of five levels of bolus consistency (using Japanese Dysphagia Diet 2013 by the JSDR Dysphagia Diet Committee) on swallowing function in healthy individuals by using high-resolution manometry (HRM).
Materials and Methods: Ten healthy subjects (average age 36.0±10.3 years) were instructed on five kinds of texture modified foods made of rice porridge. The Japanese Dysphagia Diet 2013 by the JSDR Dysphagia Diet Committee was used as a reference. The five kinds of texture modified foods were called code 0 to 5. For the texture evaluation, the participants received each food two times. Pressure and timing events were recorded with a 20-sensor HRM catheter. We analyzed the maximum swallowing pressure and contraction duration at the level of the velopharynx, tongue base, and lower pharynx, as well as the relaxation duration of the upper esophageal sphincter (UES).
Results: UES relaxation duration was significantly higher with an increase in bolus volume for every food texture. Contraction duration at the level of the velopharynx was significantly higher when swallowing 9 g compared with 6 g of code 2; was significantly higher when swallowing 6 g compared with 3 g of code 3; and was significantly higher when swallowing 9 g compared with 3 g of code 4. Contraction duration at the level of the tongue base was significantly higher when swallowing 9 g compared with 3 g of code 4. The peak pressure at the base of the tongue was significantly lower when swallowing 9 g compared with 3 g of code 2, and was significantly lower when swallowing 9 g compared with 6 g of code 2.
Conclusion: Each texture had no effect on relaxation duration of the upper esophageal sphincter, contraction duration or maximum swallowing pressure, at the level of the velopharynx, tongue base and lower pharynx. However, for every texture, increasing the bolus volume was shown to have a significant effect on increasing UES relaxation duration. UES relaxation duration can be detected by varying the bolus volumes of different textures. Contraction duration at the level of the velopharynx and tongue base increased by increasing the volume of particular textures. Maximum swallowing pressure at the tongue base decreased as particular textures increased.
