Iranian Dental Association Journal of Iranian Dental Association 3060-8201 30 3 2018 07 01 Assessment of Frequency and Anatomical Characteristics of Haller Cells in Cone-Beam Computed Tomography Scans of Patients Referring to a Private Oral and Maxillofacial Radiology Clinic During 2015-2017 100 105 10.30699/JIsdreir.30.3.100 EN Shahriyar Shahab Soodeh Sarikhani Maryam Eslami Manouchehri Parisa Yazdanpanah Journal Article 10.30699/JIsdreir.30.3.100 2018 10 08 2018 10 08 Background and Aim: Haller cells are one of the anatomical variations in the orbital area, which are important in endoscopic surgical procedures and have a role in the pathogenesis of some diseases including sinusitis and chronic craniofacial pain. The frequency of Haller cells has been reported in a wide range, which can be attributed to several factors. The purpose of this study was to determine the frequency and anatomi-cal characteristics of Haller cells.<br> Materials and Methods: This descriptive study was performed on 381 patients referring to a private oral and maxillofacial radiology clinic during 2015-2017. These patients needed cone-beam computed tomography (CBCT) for various reasons. All CBCT scans were observed by a radiologist. The results were statistically analyzed by Chi-square test using SPSS version 16.0 software.<br> Results: From 381 patients, 34 patients (8.9%) had Haller cells. Sixteen patients (47.05%) had Haller cells on the right side, 15 patients (44.11%) showed these cells on the left side, while 3 patients (8.82%) had these cells on both sides. On the right side, the oval shape showed the highest frequency (n=9; 47.3%). 36.8% and 15.7% of the right-sided Haller cells were round (n=7) and pyramidal (n=3), respectively. On the left side, the circular shape had the highest frequency (n=8, 44.4%). Furthermore, 27.7%, 16.7%, and 11.1% of the left-sided Haller cells were oval (n=5), pyramidal (n=3), and teardrop-shaped (n=2), respectively.<br> Conclusion: The prevalence of Haller cells in our study was 8.9%. Genetic and racial factors, radiographic techniques, and the age range of patients are some of the reasons for different results.