We investigated the relationship between mastication and respiration during acute nasal obstruction in infants.
Methods: The subjects were 16 healthy infants (Hellman dental age II A- II C). Electromyograms (EMG) were obtained from the masseter muscle using a surface electrode technique. The respiratory curve was obtained with a mechanoelectrical transducer for respiration. The EMG and respiratory curve were recorded simultaneously. We analyzed the respiratory rate, respiratory cycle time, relative tidal volume, masticatory rate and masticatory cycle time. The condition of nasal obstruction was simulated by pinching the nose.
Results: 1. At rest, the respiratory cycle time tended to be prolonged under acute nasal obstruction with mastication of gum, there were significant differences in the prologation (p<0.001).
2. As for the respiratory rate, at rest, this decreased during the acute nasal obstruction with mastication of gum, there were significant differences in decrease during acute nasal obstruction (p<0.05).
3. As for the relative tidal volume, at rest and mastication of chewing gum, there was an increase during acute nasal obstruction.
4. As for the masticatory cycle time, this showed a similar time both non-obstructed and nasal obstructed.
5. As for the masticatory rate, this decreased during acute nasal obstruction.
Conclusions: These results, indicated that nasal obstruction of infants affects respiration, but that nasal obstruction of infants did not show any affect on mastication.