A Study on the Association Between Accessory Maxillary Ostium and Maxillary Sinus Mucosal Thickening Using Cone Beam Computed Tomography

Background: Accessory maxillary ostium (AMO) has a major role to play in the aetiology of maxillary sinusitis. Mucosal thickening is one of the key radiographic features of chronic maxillary sinusitis. The aim of this study was to identify the location of the AMOs and investigate the association between Mucosal Thickening [MT] and AMO using Cone Beam Computed Tomography [CBCT].

Methods: CBCT scans of 400 maxillary sinuses from the records of 200 patients who seeked various dental treatments at the Thumbay Dental Hospital, Gulf Medical University, Ajman, United Arab Emirates were evaluated. The incidence, anatomical position and maximal length of accessory maxillary ostia (AMO) in the maxillary antrum were reviewed using CBCT by two examiners. The association between MTs and AMOs were also analysed.

Results: Among the 200 CBCT scans, 131 belonged to male patients and 69 scans belonged to female subjects within the age group of 18-65 years (mean age 41.32 years). AMOs were found in 142 maxillary antra (35.5 %). The inter-observer reliability for using CBCT to detect AMO was (k = 0.83). There was no significant difference in the frequency of AMOs when the age (P = 0.19) and gender (P = 0.54) distribution were considered. Sinuses with AMOs, showed significantly greater frequency of MTs (p = 0.001). AMOs with maximal length of less than 1mm were most commonly observed (51.40 %). AMOs with larger greater maximal length were associated with higher degrees of MT. The location of the AMOs, were not affected by the degree of MT.

Conclusions: The study demonstrates a clear association between degree of MT and occurrence of AMO in the maxillary sinus. However, the location of the AMO is independent of the degree of the MT. There is a greater probability of finding an AMO in the maxillary sinus if the MT in the sinus is more than 3 mm.