RESUMO
BACKGROUND: The large proportion of unilaterally affected sinus lesion is chronic sinusitis, even though a considerable number of unilateral sinus lesions include inverted papilloma, cyst, malignancy and fungal infection. OBJECTIVES: This study was designed to determine anatomically related factors of unilateral chronic sinusitis. MATERIALS AND METHODS: We obtained the CT scans in a series of 257 patients with unilaterally affected sinus lesions from July 1991 through December 1995, and retrospectively analysed 183 patients with unilateral chronic sinusitis excluding cystic or tumorous disorders, fungal sinusitis, and antrochoanal polyp. RESULTS: The major proportion of unilateral sinus lesions are simple chronic sinusitis. The CT scan reveals that bony anatomical variations of OMU are statistically significant factors related with development of unilateral chronic sinusitis. Nasal polyp is, also, one of the factors associated with unilateral chronic sinusitis. The direction of nasal septal deviation has no statistically significant relation with unilateral chronic sinusitis. CONCLUSION: These results suggest that the anatomical variations of OMU, either singly or in combination, interfere with the normal air flow and mucociliary clearance and they may contribute development of unilateral sinusitis.