Endoscopic visualization of CT-confirmed accessory maxillary ostium: a retrospective study

Background The accessory maxillary ostium (AMO) is a common anatomical variant of the lateral nasal wall and has been implicated in impaired maxillary sinus drainage, mucus recirculation, and chronic sinus pathology. Although AMO can be identified using both radiologic and endoscopic techniques, the endoscopic visualization rate of CT-documented AMO has not been well characterized. This study aimed to evaluate the endoscopic visualization rate of AMO using FFE in patients with CT-documented AMO. Method This retrospective cohort study was conducted at a tertiary referral center between January 2023 and December 2024. Patients with CT-confirmed AMO who subsequently underwent FFE were included. Patients with a history of prior sinus surgery were excluded. Demographic data, CT findings, and endoscopic visualization of AMO were collected from electronic medical records. Descriptive statistics were used to summarize the data, and categorical variables were analyzed using Chi-square or Fisher's exact tests as appropriate. Results A total of 274 patients were included, with a mean age of 34.4 ± 14.1 years; 51.8% were male. While AMO was confirmed on CT imaging in all participants by inclusion criteria, FFE visualized AMO in only 26% of cases (71/274), indicating a low endoscopic visualization rate among patients with CT-confirmed AMO. Maxillary sinus opacification was detected on CT in 49.6% of patients, while nasal polyps were present in 34.3%. No significant gender differences were observed in the prevalence of maxillary opacification or nasal polyps. Conclusion Flexible fiberoptic endoscopy demonstrated limited ability to visualize accessory maxillary ostium in patients with CT-documented AMO. While FFE remains useful for functional and mucosal assessment, CT imaging appeared to useful for anatomical identification of AMO and may be considered for comprehensive evaluation and surgical planning.