Determination of reference values of the craniovertebral junction in healthy individuals using computed tomography

Purpose: This study aims to investigate the clinical and anatomical characteristics of the craniovertebral junction in healthy individuals to establish reference data for surgical planning and evaluation. Materials and Methods: The Computed Tomography (CT) images including, dens transverse length (DTL), dens anteroposterior length (DAPL), dens height (DH), dens tip (DT), atlantooccipital joint angle (AOJA), distance between basion to opistion (BOD), axis height (AH), atlantooccipital interval (AOI), Welcher basal angle (WBA), clivus canal angle (CCA), Klaus height index (KHI), anterior atlanto-dental interval (AADI), and posterior atlanto dental interval (PADI) of 180 healthy individuals between 18-60 years were retrospectively evaluated. Results: Measurement results were found as follows: DTL 10.35±0.83 mm, DAPL 11.45±0.95 mm, DH 15.70±1.44 mm, DT 1.58±0.49 mm, AOJA 118.24±7.11°, BOD 33.58±2.79 mm, AH 34.78±2.82 mm, AOI 1.47±0.29 mm, WBA, 130.41±5.89°, CCA 160.56±9.94°, KHI 41.45±3.03, AADI 1.19±0.48 mm, and PADI, 19.47±1.84 mm, in healthy subjects, respectively. Additionally, some parameters, including DTL, DAPL, DH, BOD, AH, AADI, and PADI, were significantly higher in males than in females. DTL, DH, DT, AH, and AOI parameters showed a significant difference between ages. Conclusion: Detailed anatomical and radiological knowledge of the craniovertebral junction is crucial in various clinical disciplines, including anatomy, radiology, anesthesiology, neurosurgery, and otolaryngology, due to its complex structure and critical anatomical relationships.