Prevalence of Nasal Septal Aberrations Using Cone Beam Computed Tomography

Objectives: Cone beam computed tomography (CBCT) facilitates three dimensional imaging of maxillofacial osseous structures.  The employed field of view generates incidental imaging of  the rhino-nasal apparatus. The existence of varied anatomical details in the area may affect the patency of the nasopharyngeal airway.  The purpose of this study was to investigate the prevalence of anatomical variations of the nasal septum and assess the concomitant radiographic evidence of maxillary sinus status using cone beam computed tomography.

Methods: A systematic retrospective radiographic evaluation of the 150 dental patients was conducted who had undergone CBCT examination of maxilla for assessment of potential implant sites.  The selection criterion excluded symptomatic patients, sex or age consideration. The exposure technique employed to acquire the studies used 120KV, 24mA, 20 seconds, and a field of view of 13cm generating voxel size of 0.3mm.  The nasal septum was assessed in coronal and axial planes utilizing the Xoran software^TM provided by the manufacturer with the iCAT^TM CBCT unit employed in this study. A radiologist interpreted the acquired images. 

Results:

Sample Size	146
Deviated Nasal Septa	67.81%
Linear Septa	58.91%
Sigmoid Septa	8.90%
Septa contacting inferior turbinate	43.84%
Septa contacting middle turbinate	26.03%
Vomer spurs present	44.52%
Ostium patent	95.21%
Maxillary Sinus >4mm hyperplastic lining/opacification	21.23%

Conclusions: The study demonstrated the prevalence of 67% nasal septal deviations. The linear septal deviations occurred 7 times more often than the sigmoid type of nasal septal deviation.  The deviated nasal septum contacted the mucosa of the inferior turbinates in 43% of the cases compared to 26% middle turbinate mucosal contacts.  Vomer spurs were evident in the majority of patients who had a deviated septa with mucosal contacts with turbinate mucosa. Ninety-five percent of the patients showed existence of some patentcy of the maxillary sinus ostium even though 21% had either >4mm thick sinus lining or partial to complete opacification of maxillary sinus.