Anatomic Variations of the Paranasal Sinus Region: Evaluation with Multidetector CT

Objective: In this study, we aimed to evaluate the frequency of anatomic variations of the paranasal sinus region by using multidetector computerized tomography (MDCT). Methods: Between November 2009 and February 2012, 5832 adult patients (2980 females, 2852 males) with a mean age of 39.1 +/- 15.4 years (range; 19-85), who underwent MDCT imaging of the paranasal sinus region, were retrospectively evaluated by using the picture archiving and communication system (PACS). All the images were evaluated by three radiologists. Frequency distribution and descriptive statistics of the variants were analysed. Results: Nasal septal deviation was the most commonly detected variation (59.1%) and most were rightward (26.5%). Middle concha pneumatization was the second most commonly encountered variation (57.2%), whereas nasal septum pneumatization was the third most common one (34.8%). Maxillary sinus aplasia was detected in one patient and it was the least common variation (0.05%). Dehiscence of the maxillary nerve (0.4%) and internal carotid artery (0.5%) and sphenoid sinus aplasia (0.5%) were infrequently encountered variations in our study. Conclusion: It is important for the radiologist to know the anatomical variations of the paranasal sinus region in order to consider their possible pathological consequences. Guiding the surgeon in the preoperative period is essential to avoid potential complications.