Acoustic Rhinometric Assessment of the Nasal Valve

Abstract

The aims of this study are to assess nasal valve cross-sectional areas in healthy noses and in patients with nasal obstruction after rhinoplasty and to evaluate the effect of an external nasal dilator on both healthy and obstructive nasal valves. Subjects consisted of (i) volunteers with no nasal symptoms, nasal cavities unremarkable to rhinoscopy and normal nasal resistance and (ii) patients referred to our clinic complaining of postrhinoplasty nasal obstruction. All subjects were tested before and after topical decongestion of the nasal mucosa and with an external nasal dilator. In 79 untreated healthy nasal cavities the nasal valve area showed two constrictions: the proximal constriction averaged 0.78 cm2 cross-section and was situated 1.18 cm from the nostril, the distal constriction averaged 0.70 cm2 cross-section at 2.86 cm from the nostril. Mucosal decongestion increased cross-sectional area of the distal constriction significantly (p < 0.0001) but not the proximal. External dilation increased cross-sectional area of both constrictions significantly (p < 0.0001). In 26 post-rhinoplasty obstructed nasal cavities, only a single constriction was detected, averaging 0.34 cm2 cross-section at 2.55 cm from the nostril and 0.4 cm2 at 2.46 cm from the nostril, before and after mucosal decongestion respectively. External dilation increased the minimum cross-sectional area to 0.64 cm2 in these nasal cavities (p < 0.0001). We conclude that the nasal valve area in patients with postrhinoplasty nasal obstruction is significantly smaller than in healthy nasal cavities as shown by acoustic rhinometry. Acoustic rhinometry objectively determines the structural and mucovascular components of the nasal valve area and external dilation is an effective therapeutical approach in the management of nasal valve obstruction.

Áreas seccionais nasais de adultos sadios aferidas por rinometria acústica

“…Normal cross-sectional area values have been reported by many authors [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] , whose findings are summarized on Chart 1. Nonetheless, due to factors such as ethnic, weather, and laboratory-related differences, local reference values must be determined, as stressed by Hilberg and Pedersen 7 and Roithman 26 more recently.…”

“…The papers cited above are quite recent, and two used the same equipment employed in our study. In all others [14][15][16][17][20][21][22] , the average CSA1 values ranged between 0.60cm 2 and 0.78cm 2 . This difference may be attributed to the fact that most studies -specially the ones done longer ago -used olive-type nasal adapters which ae known to introduce nasal cavity deformation, thus leading to overestimated cross-sectional area measurements 14,29 .…”

Volumes nasais de adultos aferidos por rinometria acústica

“…Subjects were seated and with their foreheads and chin placed on a support made with orthodontic materials http://www.rborl.org.br / e-mail: revista@aborlccf.org.br [4,30] specifically for this end (figure 1), to immobilize the head in an axial plane parallel to the ground for rhinometric exams. During data acquisition subjects were asked to hold their breaths at the end of expiration while at rest.…”

“…[1][2][3][4][9][10][11][12][13][14][15] Chart 1 summarizes the main features raised in published papers and their main findings. It is evident that few studies analyzed more than one nasal cavity segment, 4,9,11,13 and only one paper 11 assessed nasopharyngeal volume.…”

“…3 The technique is used to check nasal geometry, to identify altered patency, and to monitor the results of surgical procedures on nasal and nasopharyngeal airways. [1][2][3][4][5][6][7] Hilberg e Pedersen 8 underlined the importance of creating cross-sectional and volume reference values in their recommendations to the European Rhinological Society on the use of acoustic rhinometry to analyze naso-respiratory function. Nasal volume values based on acoustic rhinometry in normal subjects have been published by various authors using different equipment to analyze nasal segments.…”