Clinical nasal obstruction and objective respiratory mode determination.

Nasal obstruction represents a considerable portion of the symptoms addressed by the otolaryngologist. It has received widespread interest in the orthodontic literature as well, because of the presumed relation between nasal obstruction and facial growth, especially vertical maxillary excess. The range of normal variation in oral versus nasal breathing has not been defined. This study attempted to correlate patient symptoms with respiratory mode. A sample of 20 symptomatic adult subjects presenting with nasal obstruction was compared to a control sample of 20 asymptomatic adults by means of SNORT (Simultaneous Nasal and Oral Respirometric Technique). Nasal resistance was significantly different between the two groups, but percent nasality (that proportion of the total volume of air breathed nasally) was a more consistent and significant finding. The relevance of these results to both clinical and basic physiology is discussed.