Superior and Anterior Hyoid Displacement During Swallowing in Non-Dysphagic Individuals

The Dynamic Swallow Study (DSS) is a methodology used to objectively and quantitatively assess swallowing kinematics during Videofluoroscopic Swallow Studies (VFSS). No DSS normative data exist delineating superior and anterior hyoid displacement (H_sup and H_ant, respectively), nor the ratio between H_sup and H_ant (SA_ratio). The aims of this study were to (1) establish normative data for H_sup, H_ant, and SA_ratio and (2) assess the effects of age, sex, and bolus size on these measures in non-dysphagic patients, within the context of DSS. VFSSs were reviewed for consecutive elderly (≥ 65 years) and non-elderly (< 65 years) male and female non-dysphagic patients. Measurements of H_sup, H_ant, and SA_ratio were made using a novel measurement methodology within the context of the Dynamic Swallow Study (DSS) protocol. Statistical analysis was performed to establish interaction effects and main effects of age, sex, and bolus size on H_sup, H_ant, and SA_ratio. Descriptive statistics (mean ± standard deviations) are outlined for H_sup, H_ant, and SA_ratio. H_sup was significantly effected by bolus size and age. Additionally, a significant three-way interaction of age, sex, and bolus size was observed. H_ant was significantly effected by bolus size and sex, but no two- or three-way interactions were present. Neither bolus size, age, nor sex significantly effected SA_ratio. Age, sex, and bolus size normative data were established for H_sup, H_ant, and SA_ratio for VFSS kinematic analysis. By outlining these measures, one can more thoroughly evaluate the areas of specific swallowing impairment, better determine the therapy targets, and track changes over time.