Septal deviation is associated with maxillary sinus fungus ball in male patients.

Fungus is one of the causes of chronic rhinosinusitis. If the fungus occupies the sinus but does not invade the sinonasal mucosa, this is called sinus fungus ball. Any association between anatomical variations and fungus ball remains unclear. Sinus fungus ball is defined as non-invasive chronic fungal rhinosinusitis occurring in immunocompetent patients, and the maxillary sinus is the most commonly affected. The etiology of maxillary sinus fungus ball remains unclear. This study assessed the potential contribution of anatomical variations, such as deviated nasal septum, concha bullosa, and Haller cell to the development of fungus ball in the maxillary sinus. Concha bullosa and Haller cell are structural variations that narrow the nasal airflow passage and contribute to chronic rhinosinusitis. The involvement of these variations has been investigated in chronic sinusitis but not in sinus fungus ball. Preoperative computed tomography findings of 103 patients with maxillary sinus fungus ball were evaluated retrospectively. Septal deviation and Haller cell were not correlated with the side of maxillary sinus fungus ball. Concha bullosa was more common on the unaffected side (p = 0.099). When we analyzed males and females separately, maxillary sinus fungus ball was more common on the concave side of the deviated septum in only male patients (p = 0.006). The high incidence of maxillary fungus ball in the concave side may reflect the consequences of the traumatic effects caused by wall shear stress of the high-velocity airflow and the increased chance of inhaling fungus spores.