Show Summary Details
Page of

Chapter 77 

Chapter 77
Chapter 77

Brandon C. Perry

and Kathleen R. Fink

Page of

PRINTED FROM OXFORD MEDICINE ONLINE ( © Oxford University Press, 2022. All Rights Reserved. Under the terms of the licence agreement, an individual user may print out a PDF of a single chapter of a title in Oxford Medicine Online for personal use (for details see Privacy Policy and Legal Notice).

date: 05 July 2022

An os odontoideum is a smooth, well-corticated ossicle located superiorly to a hypoplastic odontoid process. An orthotopic os odontoideum is located in the expected anatomic position posterior to the anterior arch of C1 with a gap between C2 and the os odontoideum. A dystopic os odontoideum is located elsewhere, often near the foramen magnum. Current evidence suggests that os odontoideum results from trauma during childhood, before the age of 5–6 years, although the etiology remains controversial. A hypertrophied and rounded anterior arch of C1 is a common associated finding.

Access to the complete content on Oxford Medicine Online requires a subscription or purchase. Public users are able to search the site and view the abstracts for each book and chapter without a subscription.

Please subscribe or login to access full text content.

If you have purchased a print title that contains an access token, please see the token for information about how to register your code.

For questions on access or troubleshooting, please check our FAQs, and if you can't find the answer there, please contact us.