# Accessory Maxillary Sinus Ostium Frequency and Correlation with Anatomical Variables and Sinus Mucosal Status: A CBCT Study

## TL;DR

This study found that accessory maxillary sinus ostia are relatively common and more frequent in men, and they correlate with abnormal sinus mucosal status and sinus dimensions.

## Contribution

The study provides new insights into the frequency and anatomical correlations of accessory maxillary sinus ostia using CBCT imaging.

## Key findings

- The frequency of accessory maxillary sinus ostia was 35.6%.
- AMO was more common in men and in sinuses with abnormal mucosal status.
- AMO presence was significantly related to the anterior-posterior dimension of the sinus.

## Abstract

The accessory maxillary sinus ostium (AMO) is one of the anatomical variations in the maxillary sinus. The acquired or congenital nature of AMO has not been proven. In theory, mucus drained from the principal ostium may reenter the sinus through the accessory ostium and cause maxillary rhinosinusitis.

The aim of the present study is to investigate the AMO frequency and its correlation with some anatomical and pathological variables in the area using cone-beam computed tomography (CBCT) images.

This was a descriptive-analytical cross-sectional study. CBCT images were obtained from 273 individuals and a total of 461 maxillary sinuses. The presence of AMOs and their relationship with age, sex, sinus mucosa condition, patency of the principal ostium, septal deviation, and sinus dimensions were measured.

The AMO frequency was 35.6% and 14.63% of sinuses had more than one AMO. AMO was more common in men. There was a statistically significant relationship between AMO presence and abnormal mucosal status of maxillary sinus. The present study showed a statistically significant relationship between the presence of AMO and the anterior-posterior dimension of the sinus.

AMO occurred more frequently in the sinuses with abnormal mucosal status. However, when the abnormal sinus mucosa has reached the nasal fontanelle, it is not possible to check the presence of AMO by CBCT images.