Factors Influencing Presence or Absence of Laterality During Pharyngeal Bolus Clearance.

PURPOSE

The aim of this study was to identify factors influencing pharyngeal laterality of bolus clearance through the pharyngoesophageal segment.

METHOD

Two swallowing trials (5-ml nectar-thickened liquid and 5-ml pudding) administered in the anteroposterior viewing plane during videofluoroscopy were extracted from a normative database of 195 healthy adult participants. Each swallow was determined as either having no laterality, right dominance/right side only, or left dominance/left side only. Descriptive measures were performed on all data variables. Chi-square tests were performed to determine the relationship between laterality and several factors, including age category, sex, race, and swallow task.

RESULTS

The majority of swallows demonstrated no laterality. No significant associations were observed between laterality and the following factors: age category, race, or swallow task. Significant differences in laterality were observed between males and females, with females more likely to demonstrate no laterality.

CONCLUSIONS

Majority of swallows in the current healthy sample demonstrated no laterality preference. If present, males were more likely to demonstrate laterality compared to females. Laterality observed during videofluoroscopy does not imply impairment if there are no other factors present influencing bolus flow into the esophagus (e.g., mass). Study findings further define typical swallowing behaviors, allowing clinicians to better delineate normal variations from true impairment. Further research should include a larger sample of individuals aged 80 years and older, as well as additional swallowing tasks, to further investigate patient- and bolus-related factors on laterality.