Upper pharyngeal airway volume and sella turcica morphology across sagittal skeletal malocclusions in healthy Egyptian adults: A retrospective three-dimensional CBCT cross-sectional study.

OBJECTIVES

Examine the associations between upper pharyngeal airway volumes, soft-palate and posterior-wall distances, and sella turcica dimensions across sagittal skeletal classes in healthy Egyptian adults.

MATERIAL AND

METHODS

A retrospective cross-sectional study in which all eligible CBCT scans from the orthodontic department of the orthodontics, Faculty of Dental Medicine, Al Azhar University were successively included between November 2025 and January 2026. Upper airway volumes, length of the soft palate, distance from the soft palate to the pharynx, distance from the epiglottis to the pharynx (DEP), and sella turcica measurements were obtained from 3D reconstructions of the CBCT scans. Two-way factorial MANOVA was used to assess the main effects and interaction between skeletal class and sex, followed by a two-way ANOVA. Tukey post hoc test was carried out if a significant effect was found. Pearson's correlation coefficient was used to assess the relationships among all measures.

RESULTS

Out of 300 scans, 180 were included. Significant main effects for skeletal class were found for the nasopharynx (P<0.05), hypopharynx (P<0.05), DEP (P<0.05), and sella turcica diameter (STI) (P<0.05). Class III subjects demonstrated the largest hypopharyngeal volumes but significantly reduced nasopharyngeal volumes (13.39±0.79cm3) and STI (10.39±0.94mm) compared to class I (P<0.05). Class II subjects exhibited significantly smaller hypopharyngeal volumes (mean 12.54±0.6cm3) compared to class I (13.97±0.76cm3) and III (14.19±0.7cm3) (P<0.05). Sex and class×sex interactions were not statistically significant for any airway or sella parameters (P>0.05). The correlations were generally weak in magnitude with few class-specific correlations were significant (P<0.05).

CONCLUSION

In this sample, the sagittal skeletal class correlated with specific airway and cranial base differences, with class III showing reduced nasopharyngeal volume, DEP, and STI, and class II exhibiting hypopharyngeal reduction.