Morphological analysis of anatomical structure of nasopharynx in cone-beam computed tomography in Korean population.

Purpose: This study evaluated the nasopharyngeal anatomy, particularly the fossa of Rosenmüller (FoR), on cone-beam computed tomography (CBCT) in a Korean population to establish normative reference data by sex and age. Materials and Methods: In CBCT images, FoR was classified into three types (A-C) for image analysis. Measurements of nasopharyngeal dimensions were performed in Types B and C. Sex- and age-related differences were evaluated using chi-square and independent t-tests, and reliability was assessed using the intraclass correlation coefficient. Results: In total, 492 CBCTs (244 males, 248 females; 20-69 years) were included. Type C was the most frequent morphology and increased with age. Types A and B were more prevalent among males than among females, whereas Type C was predominant among females (57.3%) compared with males (34.4%). Asymmetry was more frequent in males (13.9%) than in females (10.1%). Significant sex differences due to the larger males were found in the distance of the torus levatorius, the distance between the sphenopalatine notch and the right torus levatorius, and the horizontal and vertical dimensions of the FoR. No significant side-to-side differences were observed. Reliability was excellent (ICC=0.97). Conclusion: Type C was the most frequent morphology in both sexes, whereas Types A and B were more frequently observed in males than in females. These differences may indirectly contribute to sex-related disparities in nasopharyngeal carcinoma (NPC) incidence. The normative reference values may aid early detection in dental imaging, and further prospective studies including NPC patients are needed to clarify the role of nasopharyngeal morphology.