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

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.

Maxillary sinuses, multiple aspects to consider prior to bone grafting procedure: a retrospective study in a sample of a Palestinian population

OBJECTIVES

To analyze various anatomical aspects of the maxillary sinuses on CBCT volumes, mainly, the posterior superior alveolar artery (PSAA), and to compare its visibility on CBCT vs. panoramic radiographs.

MATERIAL AND METHODS

A retrospective radiographic analysis was conducted on 120 patients (240 maxillary sinuses) using their CBCT coronal views (CCV) and panoramic radiographs (CP). On CCV, the PSAA's maximum dimension (MD), vertical distance (PVD) to the alveolar crest, and bone plate thickness (T1 and T2) buccally and inferiorly to the PSAA, respectively, were analyzed. Additionally, on CCV, the ostium vertical distance (OVD) and location were recorded, and the height of the remaining bone height inferior to the maxillary sinuses (MVD) was also measured. The PSAA's visibility was evaluated and compared between CCV and CP. All these variables were studied at the apical region of the second maxillary premolar (P2), first molar (M1), and second molar (M2). Age, gender, and face side (right vs. left) factors affecting the sinus dimensions and visibility were investigated. Several statistical tests were used to analyze these variables.

RESULTS

PSAA was detected in 96.53% of the records on CCV, where it was significantly superior to CP in the detection of the PSAA structure (p value 0.000) at all sites analyzed. The PSAA's MD, PVD, T1 and T2 thicknesses, and MVD were on average 1.19 mm, 19.54 mm, 0.69 mm, 1.36 mm, and 10.25, respectively. OVD average was 31.04 mm where 42.9% of the ostia were within the mesiodistal extent of the second upper molar. No significant relation was found between different age groups, gender, and the visibility level of PSAA.

CONCLUSION

Age, gender, and the side of the face investigated showed no discernible effects on the maxillary sinus's bone thickness, vertical dimensions, or PSAA diameter among the studied Palestinian sample. As CCV was superior to CP in the identification of PSSA, preoperative evaluation of PSSA using CBCT volumes is thus recommended.

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.