Dimensional and Volumetric Analysis of the Oropharyngeal Airway in Oral Submucous Fibrosis Patients: A Cone Beam Computed Tomography Study.

Introduction Oral submucous fibrosis (OSMF) is a chronic, potentially malignant disorder associated with areca nut consumption that may extend beyond the oral mucosa to affect the oropharyngeal airway, an area still inadequately characterized using three-dimensional imaging. This study aimed to comparatively evaluate oropharyngeal airway dimensions and volume across different clinical stages of OSMF and healthy controls using cone beam computed tomography (CBCT). Methods This prospective cross-sectional study included 80 CBCT scans: 20 healthy controls (group 1) and 60 OSMF patients equally distributed across stage I, II, and III (groups 2-4). Airway volume, minimum cross-sectional area, anteroposterior and transverse dimensions were obtained using 3D airway module across axial sections. Velar length, pharyngeal depth, and oropharyngeal width were measured on mid-sagittal CBCT sections. Data were analyzed using SPSS v26.0 (IBM Inc., Armonk, New York). Continuous variables were expressed as mean ± SD. Levene's test was used to assess homogeneity of variance across groups for each parameter. Where variances were equal (Levene's p≥0.05), one-way ANOVA followed by Tukey's post-hoc test was used for intergroup comparisons. Where variances were unequal (Levene's p<0.05), Welch's ANOVA followed by Games-Howell post-hoc test was used instead, as these methods do not assume equal variances and are more robust under heteroscedasticity. Statistical significance was set at p<0.05. Results All parameters showed a progressive, statistically significant reduction from controls to stage III OSMF. Airway volume decreased from 20.90±(3.06) cm³ to 5.14(±1.87)cm³ (F=162.944, p< 0.001). Minimum cross-sectional area fell from 335.93(±64.25) mm² to 62.77(±20.49) mm² (F=154.020, p<0.001). Transverse (L-R) dimension showed the steepest decline, from 28.45(±6.71) mm to 8.37(±2.54) mm (F=178.645, p<0.001), exceeding anteroposterior reduction. Velopharyngeal ratio declined from 1.07(±0.12) to 0.46(±0.15) (F=60.194, p<0.001). Conclusions Greater OSMF severity was associated with reduced oropharyngeal airway dimensions on CBCT, predominantly in the transverse plane. Three-dimensional CBCT assessment may provide complementary information to clinical evaluation, when imaging is appropriately justified and performed with radiation-dose optimization.