Introduction

Maxillary sinus cysts are common benign imaging findings. They are usually described as rounded or dome-shaped, well-circumscribed soft-tissue opacities and often arise from the sinus floor. Reported prevalence varies substantially with population and imaging modality, and cone beam computed tomography detects more lesions than panoramic radiography [1]. Long-term follow-up studies indicate that many retention cysts regress or remain stable, supporting observation when symptoms, complications, or diagnostic uncertainty are absent [2-5]. Recent surgical evidence further suggests that anatomical location may correspond to distinct histopathological phenotypes [6].

The clinically important problem is not simply recognizing a cyst, but separating a localized cystic lesion from diffuse inflammatory rhinosinusitis and from odontogenic disease. Symptoms overlap, and nasal obstruction, facial pressure, headache, discharge, and olfactory impairment are not specific [1]. Endoscopy and cross-sectional imaging therefore complement history, particularly when ostiomeatal obstruction, mucosal thickening, reduced aeration, dental pathology, or unilateral disease is present [7].

This distinction also has potential neuro-otologic relevance. Chronic sinonasal inflammation can impair Eustachian tube function and may produce aural fullness, muffled or conductive hearing loss, otalgia, and tinnitus [8-10]. Ear-related symptoms are frequent in chronic rhinosinusitis and often improve after effective sinonasal treatment, although evidence is strongest for Eustachian tube dysfunction rather than direct sensorineural injury [9]. Vascular and endothelial causes of sensorineural hearing loss and tinnitus should remain in the differential diagnosis when audiological abnormalities are present [11].

The present study compared clinical, endoscopic, and cone beam computed tomography findings in patients with maxillary sinus cysts and patients with non-cystic rhinosinusitis. A secondary objective was to define the audiological measurements required in future prospective validation without attributing unmeasured hearing or tinnitus outcomes to the current cohort [12].

Materials and Methods

Study design and participants

The clinical component was conducted at the Department of Otorhinolaryngology of the Surkhandarya Regional Multidisciplinary Medical Center during 2022-2026. The supplied cohort comprised 120 patients: 40 classified as non-cystic rhinosinusitis and 80 classified as maxillary sinus cysts [13]. Group assignment was based on clinical assessment, nasal endoscopy, and radiologic findings. The source dissertation described 70 men and 50 women overall. Patient names and medical-record identifiers were not used in this analysis or manuscript [14-20].

Patient-level spreadsheets were used only for exploratory age and mucociliary analyses [17]. Age could be calculated for all 40 non-cystic rhinosinusitis records and 79 of 80 cyst records; one cyst record contained a biologically impossible birth year and was excluded from age-based analyses. The observed age range in the spreadsheets was 13-81 years. No imputation was performed [16].

Clinical and endoscopic assessment

Clinical assessment recorded nasal obstruction, nasal discharge, headache, facial pressure or pain, olfactory dysfunction, malaise, prior treatment, recurrence, incidental detection, and prolonged asymptomatic course [21]. Rigid nasal endoscopy with 0° and 30° optics, and additional angled optics when required, assessed mucosal hyperemia, edema, pathological discharge, ostiomeatal complex obstruction, turbinate hypertrophy, and septal deviation. Local anesthesia and topical decongestion were used according to the source protocol [20].

Cone beam computed tomography assessment

Cone beam computed tomography images were reviewed in axial, sagittal, and coronal planes, with three-dimensional reconstruction when required [22]. The assessment included the distribution of mucosal disease, sinus pneumatization, ostiomeatal complex patency, localized versus diffuse change, lesion size and margins, and attenuation in Hounsfield units [23-26]. The source dataset described cysts as dome-shaped, homogeneous, and sharply marginated; mean cyst size was 12.4 ± 4.6 mm [25].

Exploratory mucociliary analysis

The saccharin transit test and nasal absorptive-function measurement were available for the cyst cohort. A saccharin particle was placed in the anterior nasal cavity and the time until perception of a sweet taste was recorded in minutes [25]. Spearman rank correlation was used to explore age versus transit time and transit time versus absorptive function. These analyses are not tests of hearing or tinnitus [27].

Audiological relevance and proposed measurement set

Hearing ability and tinnitus were not outcomes in the supplied dissertation tables or spreadsheets [24]. Accordingly, no prevalence or treatment effect for hearing loss or tinnitus was estimated. For prospective validation, the minimum audiological set should include otoscopy, pure-tone thresholds at 0.25-8 kHz, speech audiometry, tympanometry, acoustic reflexes, the Eustachian Tube Dysfunction Questionnaire 7, and documentation of aural fullness. Participants reporting tinnitus should additionally complete the Tinnitus Handicap Inventory, with tinnitus laterality, duration, and psychoacoustic characteristics recorded [28-30]. This design would distinguish middle-ear conductive effects related to Eustachian tube dysfunction from sensorineural hearing impairment [29].

Statistical analysis

Categorical variables are reported as counts and percentages. Two-sided Fisher exact tests were used for group comparisons, and univariable odds ratios with 95% confidence intervals express the odds of a cyst diagnosis when a feature was present versus absent [30]. The between-group attenuation difference was evaluated with a Welch independent-samples t test using the reported means, standard deviations, and sample sizes [31-34]. Age and laboratory distributions were compared with the Mann-Whitney U test. Spearman rank correlation assessed age versus saccharin transit time and transit time versus absorptive function in the cyst cohort. Laboratory and functional analyses were exploratory; no multiplicity-adjusted confirmatory claim was made. Statistical significance was set at p<0.05. Analyses were performed in Python 3 with SciPy [33].

Results

Statistical analysis

The median age was 34 years (interquartile range 25-38) in the non-cystic rhinosinusitis group and 33 years (interquartile range 26.5-41.5) in the cyst group. The distributions did not differ significantly (Mann-Whitney p=0.541; Figure 1).

Figure 1: Twelve-month prosthodontic outcomes. Error bars show the reported standard deviations. The figure presents summary-level clinical data and does not imply an auditory or tinnitus treatment effect.

Clinical presentation

Inflammatory sinonasal symptoms were consistently more frequent in non-cystic rhinosinusitis. Nasal discharge, nasal obstruction, olfactory dysfunction, headache, and malaise were negatively associated with a cyst diagnosis. Facial pressure or pain alone did not distinguish the groups. Conversely, incidental detection and a prolonged asymptomatic course were strongly associated with cysts (Table 1).

Table 1:  Clinical features by diagnostic group

Exploratory laboratory profiles

Leukocyte counts were higher in non-cystic rhinosinusitis than in the cyst group (median 11.9 versus 7.04 ×10⁹/L; p<0.001). Erythrocyte sedimentation rate was also higher (median 13 versus 8 mm/h; p<0.001), as were platelet counts (median 355 versus 265.5 ×10⁹/L; p<0.001; Figure 2). These post hoc findings describe the supplied cohort and require independent confirmation.

Figure 2: Exploratory laboratory profiles by diagnostic group. Panels show leukocyte count, erythrocyte sedimentation rate, and platelet count. Boxplots show medians and interquartile ranges; whiskers extend to 1.5 times the interquartile range, and points show individual records. P values are from two-sided Mann-Whitney U tests and were not adjusted for multiple comparisons.

Endoscopic findings

Mucosal hyperemia, edema, pathological discharge, ostiomeatal complex obstruction, and turbinate hypertrophy were less frequent in the cyst group. Septal deviation was common in both groups and was not statistically discriminative (Table 2).

Table 2:  Endoscopic features by diagnostic group

Computed tomographic findings

Diffuse mucosal thickening, reduced pneumatization, ostiomeatal complex obstruction, and turbinate hypertrophy favored non-cystic rhinosinusitis, whereas localized maxillary change favored a cyst diagnosis. Septal deviation again did not distinguish the groups. Mean attenuation was +28 ± 12 Hounsfield units in rhinosinusitis and +12 ± 8 Hounsfield units in cysts; the difference was significant (Welch t=7.63, p<0.001) (Table 3).

Table 3: Cone beam computed tomography features by diagnostic group

Exploratory mucociliary finding

Among 79 cyst records with valid age and saccharin transit data, age was not associated with mucociliary clearance time (Spearman ρ=-0.09, p=0.443; Figure 3). Mucociliary clearance time was likewise not associated with absorptive function (Spearman ρ=0.05, p=0.639; Figure 4). These null exploratory findings do not establish normal nasal physiology and should not be extrapolated to the rhinosinusitis group, for which equivalent patient-level functional data were not available in the supplied spreadsheet (Figure 3,4).

Figure 3: Association between age and saccharin transit time in patients with maxillary sinus cysts. Each point represents one patient-level record with valid age and mucociliary data; the line is an ordinary least-squares visual fit. Inferential testing used Spearman rank correlation and showed no significant association.

Figure 4: Association between saccharin transit time and nasal absorptive function in patients with maxillary sinus cysts. The line is an ordinary leastsquares visual fit; inference used Spearman rank correlation.

Discussion

The study identifies a coherent pattern that separates maxillary sinus cysts from non-cystic rhinosinusitis [35]. Cysts were more likely to be incidental, minimally symptomatic, localized, sharply marginated, and lower in attenuation. Non-cystic rhinosinusitis showed diffuse inflammatory change across history, endoscopy, and imaging [36]. The strongest positive clinical associations with a cyst diagnosis were incidental detection and prolonged asymptomatic course; the strongest negative associations were diffuse mucosal thickening, pathological discharge, hyperemia, and edema.

These findings agree with earlier radiographic and cone beam computed tomography studies in which mucous retention cysts were frequently asymptomatic and located along the maxillary sinus floor, while their observed prevalence varied with imaging technique and population [37-40]. They also support the principle that imaging should be interpreted in clinical context. A dome-shaped opacity is not automatically the cause of facial pain or headache, and diffuse inflammatory changes or a dental source may require a different diagnostic pathway [38].

Recent evidence from 140 surgically treated cases further indicates that imaging-defined cyst location may correspond to distinct epithelial, inflammatory, and stromal histopathological phenotypes [39,40]. This supports location-aware assessment and targeted tissue sampling while retaining histopathology as the definitive method when excision is undertaken [35].

The attenuation difference is clinically attractive because it is objective; however, Hounsfield values on cone beam computed tomography are not as standardized as values on conventional multidetector computed tomography [41-45]. Scanner settings, reconstruction, field of view, artifacts, and calibration can shift gray values. The reported +12 versus +28 Hounsfield-unit contrast should therefore be treated as an internal cohort finding rather than a universal diagnostic threshold [42]. External validation should use prespecified acquisition parameters, blinded readers, and conventional CT calibration or phantom correction [46].

The higher leukocyte count, erythrocyte sedimentation rate, and platelet count in the rhinosinusitis comparator are biologically compatible with a more inflammatory phenotype [47,48]. However, these variables were selected after inspection of the available spreadsheet, treatment status and comorbidities were not modeled, and multiple laboratory comparisons were not corrected [43]. The boxplots should therefore be interpreted as descriptive, hypothesis-generating visualizations rather than diagnostic cutoffs.

Audiological relevance

The present cohort cannot answer whether maxillary sinus cysts cause hearing impairment or tinnitus [49,50]. Nevertheless, the comparison is relevant to an otology-focused readership because the inflammatory phenotype showed more ostiomeatal obstruction, edema, and discharge, which may coexist with nasopharyngeal inflammation and Eustachian tube dysfunction [30]. Meta-analytic evidence suggests that approximately half of selected patients with chronic rhinosinusitis may meet a symptom threshold consistent with Eustachian tube dysfunction, and several studies have reported improvement in ear fullness and related otologic symptoms after endoscopic sinus surgery [51]. Eustachian tube dysfunction can produce negative middle-ear pressure, conductive hearing loss, aural fullness, and tinnitus; it should not be equated with sensorineural hearing loss without audiometry and tympanometry [17].

A 2026 population-based analysis also reported an association between prior chronic rhinosinusitis or allergic rhinitis and tinnitus, but observational association does not establish that a maxillary sinus cyst causes tinnitus. A defensible follow-up study should compare cyst and rhinosinusitis groups using pure-tone average, air-bone gaps, tympanometric type, ETDQ-7, and THI at baseline and after treatment [52]. This would align the rhinologic question with the International Tinnitus Journal while preserving causal and measurement discipline.

The differential diagnosis should also consider non-rhinologic causes of sensorineural hearing loss and tinnitus. Shodmonkulova and colleagues have demonstrated the clinical relevance of vascular and endothelial mechanisms in auditory dysfunction and emphasized combined audiometric, tinnitus, and vascular assessment in appropriately selected patients [33].

Strengths and limitations

Strengths include direct comparison of two clinically overlapping sinonasal conditions, concordant assessment across symptoms, endoscopy, and imaging, and effect estimates that quantify rather than merely describe group differences. The study also avoids claiming audiological outcomes that were not measured [53].

The main limitations are the single-center observational design, unequal group sizes, absence of a prespecified diagnostic model or external validation cohort, and lack of patient-level data for several aggregate variables. Sex-specific and group-specific age summaries were not consistently available across source tables. One biologically impossible birth-year value was excluded from age analyses [54]. The rhinosinusitis spreadsheet included heterogeneous diagnostic labels, so the comparator is described conservatively as non-cystic rhinosinusitis. Individual computed tomographic attenuation values were unavailable; therefore, no attenuation boxplot or patient-level receiver operating characteristic analysis was possible. Laboratory visualizations were post hoc and potentially confounded, while functional scatter plots were restricted to the cyst cohort. Finally, no otoscopy, pure-tone audiometry, tympanometry, ETDQ-7, THI, or tinnitus phenotype was collected, preventing conclusions about hearing or tinnitus [53,54].

Conclusion

Maxillary sinus cysts are distinguished from non-cystic rhinosinusitis by an incidental or prolonged asymptomatic course, limited endoscopic inflammation, localized imaging change, and lower mean lesion attenuation. Diffuse mucosal thickening, reduced pneumatization, pathological discharge, and ostiomeatal obstruction favor inflammatory rhinosinusitis. These findings support integrated clinical, endoscopic, and imaging interpretation rather than reliance on a single symptom or opacity. Prospective validation should incorporate objective hearing, middle-ear, Eustachian-tube, and tinnitus measures before any audiological claim is made.