Oral and pharyngeal transit time as a factor of age, gender, and consistency of liquid bolus

Abstract

Introduction: The oral transit time (OTT) and pharyngeal transit time (PTT) are measures that indicate the time taken for bolus transit in oral and pharyngeal cavities, respectively. These measures vary with respect to bolus type and quantity and reflect on the efficiency of the swallow. Objectives: The study aimed to compare OTT and PTT measures for thin (water) and thick (honey) liquid bolus consistencies in 88 typical participants (44 typical adults and 44 typical geriatric persons including males and females) and 10 persons with swallowing disorders. Materials and Methods: OTT and PTT measures for liquid bolus were derived using the equipment Digital Swallowing Workstation-Swallowing Signal Laboratory (DSW-SSL) (Kay/Pentax, Lincoln, New Jersey) Model 7120. In the absence of cited standard procedures to measure OTT and PTT, the measures of OTT and PTT were specifically defined in this study based on the measures obtained from three modules/tests of the DSW-SSL: (a) Tongue array (used to measure the tongue pressure during swallow), cervical auscultation (used to measure the swallow sound), nasal cannula (used to measure the respiratory-swallow coordination). Results and Discussion: The mean group scores of OTT and PTT measures were compared across gender, age, and consistency of bolus and treated with the appropriate statistical procedure. Results revealed that: (i) PTT for honey was longer than water in typical adults and geriatric persons. (ii) There was no significant difference in OTT for honey across age groups. (iii) Atypical patterns in the morphology of tongue pressure, swallow sound and respiratory-swallow coordination during swallow were noted across age and consistency of bolus in typical and atypical population. Conclusion: The OTT and PTT measures can serve as sensitive indices to understand swallow physiology in oral and pharyngeal phase. Increase in PTT is observed for thicker liquid like honey. There are more instances of nonhomogenous patterns across typical and atypical swallows for tongue pressure, swallow sound, and respiratory-swallow coordination.