Morphometry of the hypoglossal canal, occipital condyle, and foramen magnum

The present study was undertaken to determine the detailed morphometry of occipital condyle (OC), hypoglossal canal (HC), and foramen magnum (FM) in Turkish-Caucasian skulls: measurements were taken from 59 dry skulls of unknown sex. There was no significant difference (P>0.05) in measurements taken from the right and left sides, consequently the overall means and associated standard deviations were calculated. The length of the HC was 9.9±1.9 mm and the HC intracranial and extracranial diameters were 6.5±1.3 mm and 6.6±1.1 mm, respectively, with the angle of the HC to the sagittal plane being 45.6±4.6 degrees. The distances from the intracranial and extracranial ends of HC to the jugular foramen were 13.3±3.3 mm and 8.4±2.0 mm, respectively, whereas the distances from the HC to the jugular tubercle, opisthion and basion were 12.2±2.2 mm, 29.2±2.6 mm, and 16.5±1.8 mm, respectively. The distances from the intracranial end of the HC to the posterior, anterior, inferior margins of the OC were 12.3±2.4 mm, 11.2±1.6 mm, and 9.4±1.2 mm, respectively. The anteroposterior length and transverse width of the OC were 24.5±2.5 mm and 13.1±1.6 mm, and the angle of the OC to the sagittal plane 31.5±5.1 degrees; the mean sagittal intercondylar angle was 62.2 degrees. The anterior and posterior intercondylar distances were 22.6±3.9 mm and 44.2±3.2 mm. The anteroposterior and transverse diameters of the FM were 34.8±2.2 mm and 29.6±2.4 mm, giving a mean FM index of 1.2. The presence or absence of a septum in the HC, protrusion of OC into the FM and the presence of condylar foramen were also determined. Detailed morphometric analysis will help in the planning of surgical intervention involving the skull base safer and easier. Copyright © 2006 by Lippincott Williams & Wilkins