Study population
Participants included 159 patients (81 males; 78 females). Age ranged from 6 to 96 years, with an average age of 46.8 years (Table 1). Accessory maxillary sinus ostia in superior meatus were detected in 66 of 151 (41.5%) participants, of which 32 were males and 34 were females. Among the 66 cases with accessory ostia, two-thirds were found to be bilateral and one-third was unilateral (Table 2). Among the unilateral cases, 13 were in the left nasal cavity and nine were in the right.