Clinical and Imaging Features of Ethmomaxillary Sinus Compared to Haller’s Cell

Purpose Understanding the anatomy of the paranasal sinuses and their variations is essential to achieving safe and effective endoscopic sinus surgery. The ethmomaxillary sinus (EMS) is a relatively under-researched anatomical variation. This study investigated the prevalence, clinical features, and effect of EMS on the maxillary sinus in comparison with Haller’s cells. Methods Patients who visited the Rhinology Clinic at our hospital for rhinologic symptoms between January 2020 and December 2020. Computed tomography (CT) scans of paranasal sinuses were obtained at 1 mm-section thickness. Using CT scans, we investigated the clinical features of EMS, measured maxillary sinus volume, and analyzed the presence of maxillary sinusitis. Results EMS was observed in 26 of the 250 patients (10.4%). The male-to-female ratio was equal. The age ranged from 18 to 83 years (mean age, 56.3). Of the patients with EMS, 65.4% were unilateral and 34.6% were bilateral. The prevalence of Haller’s cells was similar to that in EMS (10.8%). In the analysis of patients with unilateral EMS, the EMS side was found to have a significantly reduced maxillary sinus volume compared to the opposite side, whereas the difference was not significant in Haller’s cells. There was no significant relationship between EMS or Haller’s cells and maxillary sinusitis. Conclusions EMS can significantly affect maxillary sinus volume. Therefore, surgeons should thoroughly review PNS CT scans before paranasal sinus surgery to determine the presence and features of EMS.