Study design
This retrospective study included patients visiting the outpatient
department of Otolaryngology Head and Neck Surgery, Shuang Ho Hospital,
Taipei Medical University. Patients visited between January and April
2020 with a chief complaint wherein chronic rhinosinusitis was
suspected. We selected cases according to inclusion criteria with a
clinical diagnosis of chronic rhinosinusitis confirmed by
high-resolution computed tomography (HRCT) scan of paranasal sinuses.
Bilateral accessory maxillary sinus ostia were viewed in axial and
coronal sections. (Figure 1). Images with suspicion of accessory
maxillary sinus ostia in superior meatus were reconstructed by
three-dimensional (3D) simulation to confirm the existence of accessory
ostia (Figure 2). Patients who had systemic diseases such as cystic
fibrosis, previous sinus surgery, acute sinusitis, maxillofacial trauma,
inverted papilloma, cystic fibrosis, choanal atresia, or sinus anomalies
were excluded. Finally, 159 patients were included for analysis.