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Abstract

Objectives: This study evaluated nasopharyngeal anatomy on large field-of-view (FOV) CBCT, (obtained from the University of British Columbia’s Doctor of Dental Medicine and Graduate programs), validated a measuring system, classified Fossa of Rosenmüller (FoR), quantified morphometric parameters, and created a 3D visual library. Hypotheses: the newly developed CBCT linear measuring system is reliable for assessing nasopharyngeal symmetry; sides of the Eustachian Tube, FoR, and Anterior Wall triangles are symmetrical; FoR morphology, classified via Takasugi, shows variability; sex-based differences exist in volume and surface area; CBCT positioning/acquisition errors can be identified for quality improvement. Methods: A total of 384 large field-of-view CBCT scans (10×5 cm and 10×10 cm) from the University of British Columbia were reviewed; 84 met the inclusion criteria. DICOM datasets were segmented and analyzed. Nine standardized linear measurements were developed and recorded, and triangular modelling defined the Eustachian Tube, FoR, and anterior wall regions. Volume, surface area, and Takasugi classification were assessed. Results: A linear measuring system was developed; the FoR span and The Fossa of Rosenmüller triangle exhibited the highest variability demonstrated the highest variability (SD ±10.3 mm), while bilateral symmetry remained consistent. The mean nasopharyngeal volume was 6,757.7 mm³ (SD ±2,139.4) and surface area 2,815.4 mm² (SD ±1,031.5), with no significant sex differences in volume or surface area. Takasugi classification revealed Type C predominance overall, with notable distribution differences by sex and age. A visual library of all models was created. Quality assurance review identified frequent CBCT positioning errors, prompting updated imaging protocols. Conclusions: CBCT-based morphometric and classification analysis reveal substantial variability in the FoR and confirm a higher prevalence of Type C morphology in older females. Standardized measurement protocols, combined with quality assurance initiatives, can enhance diagnostic consistency and reduce patient exposure.