Investigation of the accessory maxillary ostium: a congenital variation or acquired defect?

Evaluation of the relationship between the presence of an accessory maxillary ostium and the presence and types of nasal septum deviation: A computed tomography study

OBJECTIVE

The maxillary accessory ostium (AMO) has been associated with chronic rhinosinusitis and nasal septal deviation (NSD), but AMO may also be present in healthy individuals. AMO's purpose, origin, and effects are uncertain. This study aimed to investigate the types and frequency of AMO and NSD, as well as their relationship.

METHODS

In our retrospective, single-center study, paranasal sinus tomographs performed in our clinic between 2022 and 2023 were scanned, and 200 patients who met the inclusion criteria were evaluated in terms of AMO direction (right/left), accessory ostium location (superior/middle/inferior 1/3), presence of NSD, and deviation type according to the Mladina index.

RESULTS

60.5% of the patients were female and 39.5% were male. AMO distribution was similar between the groups (p>0.05). There was no significant correlation between the presence and localization of AMO and the presence of NSD (p>0.05). NSD was detected in 93 patients (89.4%) with AMO and 78 patients (81.3%) without AMO (p=0.16). The distribution of NSD presence and types was similar in right or left localization, AMO (+) and AMO (-) patients (p>0.05).

CONCLUSION

The evidence that AMOs cause chronic sinusitis and FESS failure is insufficient and cannot explain the presence of AMOs in healthy individuals or children. There are very few studies in the literature examining the NSD-AMO relationship. In our study, high rates of NSD and AMO were found in individuals without paranasal disease, but no statistically significant relationship was found between the presence, location, and type of NSD and AMO. Early-onset, long-term prospective studies on the relationship between NSD and AMO may help to explain the etiopathogenesis of paranasal diseases that reduce quality of life.

Relationship of the accessory maxillary ostium to mucosal thickening and maxillary sinus cysts: a 3D segmentation study

OBJECTIVES

We aimed to investigate the relationship between the presence of the accessory maxillary ostium (AMO) with mucosal thickening (MT) and maxillary sinus cysts (MSCs).

STUDY DESIGN

This single-center retrospective study included patients who underwent paranasal sinus computed tomography (CT) between November 2022 and February 2023. We excluded patients with natural maxillary ostium (NMO) occlusion. Two radiologists evaluated the presence of AMOs, MT, and MSCs in CT images and measured their dimensions using a three-dimensional volumetric analysis program.

RESULTS

We included 125 patients (mean age: 36.47 ± 16.0 years; male/female: 67/58). In total, 65 patients (52%) had single or multiple AMOs. No significant relationship was found between the presence of an AMO and the presence of MT on either side (P ≥ .306). There was a statistically significant difference between the presence of an AMO and MSC on the right side (P = .002), but not on the left side (P = .477). The diameter of the AMO and the distance from the AMO to the maxillary sinus floor were not correlated with mucosal thickness or MSC volume, but the distance from the AMO to the sinus floor had a small positive correlation with total maxillary sinus volume.

CONCLUSIONS

The presence of an AMO and its increased diameter may not contribute to ipsilateral maxillary sinusitis in patients whose unilateral or bilateral NMOs are not occluded.

The anatomical variations of paranasal sinuses may be related to the formation of antrochoanal polyp by computed tomography imaging study

Background

There is little investigation into the connection between anatomic variations and the development of antrochoanal polyp (ACP), and the etiology of ACP remains unclear. The study aims to explore the relationship among anatomic variations, maxillary sinus volume, nasal meatus-related parameters, and the occurrence of ACP.

Methods

There were 127 patients included in this retrospective cross-sectional study with unilateral ACPs hospitalized at Shandong Provincial ENT Hospital between February 2010 and February 2020. Evaluation indicators included anatomic variations, maxillary sinus volume, and nasal meatus-related parameters in 45 children and 82 adults, which were evaluated twice by 3DSlicer software. Parameters were assessed using the Kolmogorov-Smirnov test, followed by paired t-test and Chi-squared test for multiple comparisons.

Results

Significant differences were found in the accessory maxillary ostium (AMO) and maxillary sinus retention cyst between two sides (both P<0.001). Maxillary sinus volume and sex had an association of statistical significance on adults' ACP side (P=0.026) and non-antrochoanal polyp (non-ACP) side (P=0.032). The affected side's maxillary sinus volume was significantly larger than the healthy side (P<0.001). The length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate of the ACP side was larger than the non-ACP side in children (P=0.044). Males' length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate of the ACP side was considerably greater than the healthy side (P<0.001). The length from the maxillary sinus orifice to the plane of the most lateral margin of the middle turbinate (P=0.014) and the length from the inferior turbinate to the nasal septum (P=0.013) on the non-ACP side was higher than the affected side in adults. Males' length from the inferior turbinate to the nasal septum was higher on the healthy side than the affected side (P<0.001). Males had a greater maximum length from the maxillary sinus lateral wall to the nasal septum (P=0.024) and the length from the inferior turbinate to the nasal septum (P=0.003) on the non-ACP side than females. Males had a larger maximum length from the maxillary sinus lateral wall to the nasal septum on the ACP side than females (P=0.011).

Conclusions

In our study, the occurrence of the AMO, the maxillary sinus's expanded size, and the stenosis of the associated channels around the ostiomeatal complex and common meatus are regarded as probably connected to the formation of ACPs. In addition, the anatomic variations that involve the ostiomeatal complex and may lead to a change in maxillary sinus pressure and nasal ventilation are important factors in the formation of ACPs.

Evaluation of Anatomical Variations of the Maxillary Sinus in Patients With and Without Mucous Retention Cyst

Objectives: Mucous retention cyst (MRC) is a benign and self-limited lesion that can be caused by many risk factors, including anatomical variations of the sinonasal region. This study aims to investigate the relationship between anatomical variations and the presence of MRC. Materials and Methods: In total, 2109 sinonasal cone beam computed tomography images were evaluated for the presence of MRC, and the sinonasal anatomical regions such as the osteomeatal complex (OMC), infundibulum length, ostium height, the diameter of the ostium, the presence of accessory ostium, concha bullosa, and mucosal thickening of the maxillary sinuses. Shapiro-Wilk normality test, independent sample t-test, and chi-square test were used for statistical analysis, and P < .05 was considered significant. Results: The prevalence of MRC was 119 (5.6%) cases. The average diameter of the ostium in cases with and without MRC was 0.49 ± 0.41 mm and 0.99 ± 0.76 mm, respectively, which showed a significant inverse relationship(P < .001). A significant relationship was found between the septum deviation, the ostium height, the concha bullosa, and the accessory ostium with the presence of MRC (P < .001). Conclusions: Sinonasal anatomical variations such as ostium diameter, ostium height, septal deviation, the presence of accessory ostium, and concha bullosa can cause MRC development, and considering that surgery may be necessary in some cases; this could be of great importance to clinicians and surgeons for treatment and prevention of development or recurrence of these pseudocysts in patients.

Anatomical Characteristics of the Accessory Maxillary Ostium in Three-Dimensional Analysis

Background and Objectives: The accessory maxillary ostium (AMO) can interfere with ventilation and drainage of the maxillary sinus, and therefore the importance of evaluating the anatomical features of the AMO has been emphasized. This study aimed to evaluate anatomical characteristics of the AMO together with the natural ostium (NO) using three-dimensional (3D) analysis and to assess the relationship between the AMO and maxillary sinus pathologies. Materials and Methods: This retrospective study included 394 sinuses in 197 patients. Using 3D computed tomography images, the prevalence of the AMO and concurrent sinus pathologies were examined. For patients with an AMO, 3D spatial positions of the AMO and NO related to adjacent anatomic structures and dimensions of the AMO and NO were evaluated. Results: A total of 84 sinuses showed single or multiple AMO, with a prevalence of 21.3%. The AMO was located superiorly by 30.1 mm from the maxillary sinus floor, inferiorly by 1.3 mm from the orbital floor, and posteriorly by 22.4 mm from the anterior sinus wall. The AMO was located 5.4 mm posteriorly and 0.7 mm inferiorly from the NO. On the same coronal plane as the NO or AMO, height from the maxillary sinus floor to the NO and AMO ranged from 19.4 to 45.8 mm and 14.5 mm to 41.9 mm, respectively. The mean horizontal and vertical dimensions were 5.9 mm and 4.6 mm for the NO and 2.8 mm and 3.0 mm for the AMO. We detected a significant association between the presence of the AMO and the mucosal thickening (p = 0.029). Conclusions: The results of this study suggest that, although the AMO and NO are mostly located in positions that do not limit sinus-related surgeries, such as maxillary sinus floor augmentation, the AMO and NO are also found in lower positions, which may be a detriment to the postoperative physiological function of the maxillary sinus and affect treatment outcomes.