Characterization of Occipital Condyle and Comparison of its Dimensions with Head and Foramen Magnum Circumferences in Dry Skulls of Iran Caracterización del Cóndilo Occipital y Comparación de sus Dimensiones con la Circunferencia de la Cabeza y Foramen Magno en Cráneos Secos de Irán

BAYAT, P.; BAGHERI, M.; GHANBARI, A. & RAOOFI, A. Characterization of occipital condyle and comparison of its dimensionswith head and foramen magnum circumferences in dry skulls of Iran. Int. J. Morphol., 32(2):444-448, 2014.SUMMARY: The occipital condyle (OC) is an important area in craniovertebral surgery, but its anatomical features and theprocedures concerning the OC have not been studied in detail yet. The aim of this study was to revisit the anatomy of the occipitalcondyle region and assess variations of the surrounding structures. Observations, on fifty dry skulls (dried specimens, 100 sides) anddetermined of condyle measurements. The mean length, width and height of occipital condyle were found to be 19.43±3.27 (right),19.28±3.57 (left), 9.21±1.97 (right) 9.40±1.87 (left), 7.21±1.9 (right) and 7.33±2.74 mm (left), respectively. There were significantdifferences between right and left occipital condyles. The mean anterior intercondylar distance and posterior intercondylar dis tance weremeasured as 15.39±7 and 35.60±8.4 mm, respectively. Variations of occipital condyle shapes were kidney like (34.4%), S-like (25.6),triangular (13.3%) oval (10.0%), ring like (7.8%), eight like (6.7%) and deformed (2.2%) respectively. The condylar fossa prese nted in60% of dry skull, 24% in right side and 36% in left side and also the condylar foramen was found in 60% of the specimens studie d. Therewas no relation between the circumference of the head and the length of OC but we found relation between the circumference of t he headand the width of OC (0.527) and foramen magnum circumference (0.433). The OC and FM are the main bony structures obstructing th esurround of the brainstem. The differences in the size and the shape of occipital condyle have some differences and also similaritiesamong racial subgroups. The posterior condylar vein may act asymmetrically. The correlation of the size of foramen magnum with thewidth of occipital condyles shows the importance of occipital condyle for lateral movements besides antero-posterior movements.KEY WORDS: Skull base; Foramen magnum; Occipital bone; Iran.