Inclination of the odontoid process in the pediatric XXXX .

@entity1 @entity3976 @entity1644 @entity1645 @entity65461
OBJECT: The quantitative analysis of odontoid process angulation has had scant attention in the @entity1645 population. In this study the authors sought to elucidate the correlation between posterior angulation of the odontoid process and @entity1 with @entity1645 . METHODS: Magnetic resonance images of the craniocervical junction obtained in 100 @entity1 with @entity1645 and in 50 @entity1 with normal intracranial anatomy (controls) were analyzed. Specific attention was focused on measuring the degree of angulation of the odontoid process and assigning a score to the various degrees. Postoperative outcome following posterior cranial fossa decompression was then correlated to grades of angulation. Other measurements included midsagittal lengths of the foramen magnum and basiocciput, the authors' institutions' previously documented @entity65461 line (a line drawn perpendicular to one drawn between the basion and the posterior aspect of the C-2 body), level of the obex from a midpoint of the McRae line, and the extent of @entity3976 . Higher grades of odontoid angulation (retroflexion) were found to be more frequently associated with @entity1644 and particularly holocord syringes. Higher grades of angulation were more common in female @entity1 and were often found to have obices that were caudally displaced greater than three standard deviations below normal. CONCLUSIONS: These results not only confirm prior reports of an increased incidence of a retroflexed odontoid process in @entity1645 but quantitatively define grades of inclination. Grades of angulation were not found to correlate with postoperative outcome. It is the authors' hopes that these data add to our current limited understanding of the mechanisms involved in hindbrain herniation.
