The Nasal Airflow in Noses with Septal Perforation: A Model Study

Abstract

Background: Septal perforation is a common clinical problem in rhinology. Affected patients suffer from a dry nose, crusts as well as recurrent epistaxis and sometimes an inspiratory whistle. The aim of this study was to investigate the underlying flow dynamic mechanisms. Methods: The physical flow effects of such pathologies were examined in functional nose models (box models) and anatomically exact models of the nose. Therefore, septal perforations of different sizes and localisations were studied in straight and deviated nasal septa. Results and Conclusions: It could be seen that the localisation of the perforation has no impact on the flow pattern. In large septal perforations, the air jet collides with the posterior edge of the perforation and disintegrates turbulently. Since airflow is physiologically turbulent in the posterior part of the nose, posterior perforations do not cause clinical complaints. The inspiratory whistling sound during respiration is based on the principle of a lip whistle. Large perforations do not cause a whistling sound. The necessary high flow velocity needed in large perforations is usually not achievable.

Impact of Airflow Communication between Nasal Cavities on Nasal Ventilation

“…The accelerated airflow would reduce the contact time of airflow on the mucosa and increased wall shear stress would augment the stimulation of airflow to the nasal mucosa, both of which would damage the physiological function of the nasal cavity. Both Lee et al [6] and Grutzenmacher et al [7] considered that the impact of airflow communication in septum perforation correlated with the size but not the location of perforation. However, their researches were limited to the anteroposterior direction.…”

“…The high wall shear stress is always located in the posterior region of perforation, which could explain drying and epistaxis. Several perforation models with different sizes and locations have been investigated, and it has been confirmed that the devastating symptoms are correlated with the size of perforation but not with location [6,7,8]. …”

Fibroscopic findings in patients following maxillary osteotomies in orthognathic surgery

“…But despite the wide range of techniques proposed for the only curative alternative, which is surgical, the results are not always satisfactory as is clear from the different procedures recorded in the literature (Warren et al, 1987;Schendel and Carlotti, 1991). Therefore, the main therapeutic approach is preventative, involving early detection, given that the main cause of septal perforation is surgery of the nasal septum, followed by the use of nasal decongestion sprays and intranasal steroids that are widely used to relieve symptoms after surgery involving nasal congestion and breathing difficulties (as it is the case in the immediate postoperative period following orthognathic surgery) (Grützenmacher et al, 2001).…”

“…From then on different authors have studied the effects on nasal airflow through rhinomanometry, acoustic rhinometry, fluid dynamic experiments and functional nasal models (Schendel and Carlotti, 1991;Erbe et al, 2001;Grützenmacher et al, 2001).…”

Effects of septal perforation on nasal airflow: computer simulation study

“…10 These authors assessed septal perforations of varying sizes and locations, with and without septal deviation. Streamlines were found to 'bump' towards the posterior border of the perforation, causing turbulence which increased with increasing perforation size.…”