Purpose: The purpose of this study was to determine the frequency of MRCs of the maxillary sinus using panoramic radiographs.

Materials and Method: A total of 631 panoramic radiographs were selected from a secondary database from a private radiology clinic and analyzed by two specialists in dental radiology according to gender, age, month, relative air humidity, and mean temperature.

Results: A total of 87 (6.89%) radiographic images were suggestive of MRCs. Thirty-five MRCs (40.22%) were detected on the right side, 10 (11.49%) on the left side and 42 (48.29%) on both sides. A high frequency was detected in female participants (n=45 51, 72%), those aged 18-35 years (n=31 35, 63%) and those from August (n=24 27.59%) and July (n=22 25.29%). 

  Conclusion: The frequency of MRCs was low, and no statistically significant correlation was found between the prevalence of MRCs and the studied variables with the exception of the mean temperature