Introduction
The natural ostium of the maxillary sinus is an anterior part of the posterior fontanelle and extends transversely with an oval shape toward the inferior part of the ethmoid infundibulum. In routine nasal endoscopic examinations, the ostium of the maxillary sinus is not typically visible.1 An accessory maxillary ostium is an anatomical variant commonly observed in the middle meatus that potentially contributes to the development of chronic rhinosinusitis.2,3 However, there is a lack of clarity about the causal relationship between accessory ostia and chronic rhinosinusitis.
Research has systematically evaluated the pathophysiology of chronic rhinosinusitis and has attributed it to aberrant interactions between environmental factors and the host immune system. Accessory or secondary ostia are defined as defects in the fontanelle region of the lateral nasal wall.4 It has not yet been determined if accessory ostia are a congenital anatomical variant or if they are acquired. It has been postulated that accessory ostia are often found in the posterior nasal fontanelle of the middle meatus, and they may be unilateral or bilateral.5,6
Our evaluation of accessory maxillary sinus ostia highlighted some accessory ostia in the superior meatus. Previous studies conducting cadaver evaluations, computed tomography examinations, and endoscopies have reported various incidences of accessory maxillary sinus ostia in the middle meatus.7-9 Accessory ostia in the maxillary sinus have been associated with chronic maxillary sinusitis, and these ostia can cause recirculation of mucus, leading to the recurrence of sinusitis.10,11 Studies based on computed tomography have also indicated that accessory maxillary sinus ostia are significantly associated with chronic maxillary sinusitis.8,12 Therefore, any interventional maxillary sinus surgery must be supported by an in-depth knowledge of anatomical variations in the accessory maxillary sinus ostia of the patient to ensure maximum results and to prevent recurrence.7However, there are few reports on accessory maxillary sinus ostia in the superior meatus and the association with chronic rhinosinusitis. Thus, this study investigated the incidence of accessory maxillary sinus ostia in the superior meatus of patients exhibiting clinical and radiological signs of maxillary sinusitis and associations with the severity of chronic rhinosinusitis.