[The relationship between wearing complete dentures and swallowing function in elderly individuals: a videofluorographic study].

The role of complete dentures in masticatory function is well established, but their effect on swallowing has been little examined. This study investigated the effect of complete dentures on swallowing in the elderly. Lateral projection videofluorography (VF) was performed for nine healthy edentulous elderly volunteers (mean age 73.9 +/- 2.9 years) while they swallowed 8 ml of liquid and paste barium with and without complete dentures. A total of 35 VF records were analyzed for temporal and spatial measurements of oropharyngeal motion during swallowing. The tongue tip contacted the inside of the lip between the upper and lower alveolar ridges during swallowing without but not with complete dentures. The hyoid moved further upward (P = 0.002) during swallowing without dentures (liquid: 5.85 +/- 3.99 mm, paste: 6.41 +/- 5.25 mm) than with dentures (liquid: 3.70 +/- 4.57 mm, paste: 3.69 +/- 4.07 mm). The larynx moved further forward (P = 0.044) during swallowing without dentures (liquid: 6.39 +/- 2.58 mm, paste: 6.46 +/- 2.87 mm) than with dentures (liquid: 5.34 +/- 2.04 mm, paste: 5.93 +/- 1.50 mm). The timing of the movements of these structures was not affected by the presence of the dentures or bolus consistency. These results showed that the hyoid and larynx moved more in swallowing without than with complete dentures, perhaps because of tongue tip protrusion when not wearing dentures. These findings suggest that complete dentures have a significant effect on swallowing function as well as masticatory function in elderly individuals.