Laterality of swallowing in healthy subjects by AP projection using videofluoroscopy.

Although anteroposterior projections in videofluoroscopic examination of swallowing (VF) provide clinically important information, the laterality of swallowing in healthy subjects has not been examined fully to date. One hundred sixty-seven healthy volunteers were prospectively studied. The subjects were asked to swallow 5 ml of barium solution three times while X-ray images were taken that showed the pathway of the solution from the pharynx into the esophagus to assess the laterality of swallowing. We classified patterns of swallowing into three types according to passage in the pharyngoesophageal segment as indicated by width: RD (right-side-dominant flow), LD (left-side-dominant flow), and NL (no laterality in flow). Fifty-eight percent of the subjects were classified as NL, 35% as LD, and 7% as RD. The ratio of types in women was NL:LD:RD = 7:2:1. There were no significant differences among the groups according to age. Although classifications in young men (age = 20-30 years) tended to be the same as in women regardless of age, ratios of LD tended to increase with age; 71% of elderly adults (age = 51-75 years) were classified as LD. These results demonstrate laterality in normal swallowing and will be helpful in determining treatment strategies for the patients with dysphagia.