[Effect of adenoid hyperplasia on nasal airflow].

BACKGROUND

Adenoid hyperplasia is one of the most common reasons for nasal obstruction in childhood. The consequences of a nasopharyngeal obstruction on the airflow in the nasal cavity and the epipharynx were investigated.

MATERIALS AND METHODS

In a model of a nose we conducted experiments with adenoids of different size, documenting their influence on inspiratory and expiratory nasal flow. Rhinoresistometry was performed to obtain further information concerning resistance and turbulence.

RESULTS

The flow experiments showed no alterations of the inspiratory nasal flow regardless of adenoid size. Instead the adenoid had a significant influence on the direction of the expiratory nasal flow in the cavity. Depending on the extension of the hyperplasia, parts of the nasal cavity were excluded from the flow. Rhinoresistometry showed that relation between nasopharyngeal obstruction and nasal resistance was nonlinear.

CONCLUSION

Adenoid hyperplasia affects only expiratory nasal flow. In our model a critical mass seemed to be reached in case of more than 60% nasopharyngeal obstruction. A narrowing of the epipharynx up to 50% of its volume has no significant effects on nasal resistance.