1. Os Odontoideum as a Consequence of a Posttraumatic Displaced Ossiculum Terminale by Eiji Wada, Takashi Matsuoka, and Hideo Kawai J Bone Joint Surg Am Volume 91(7):1750-1754 July 1, 2009 ©2009 by The Journal of Bone and Joint Surgery, Inc.

2. Illustration depicting the normal growth centers of the second cervical vertebra. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

3. Lateral radiograph of the cervical spine, made six days after the injury, demonstrating an atlantoaxial interval of 4 mm without obvious fracture. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

4. Axial computed tomography scan showing a radiolucent line at the tip of the odontoid process. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

5. Three-dimensional computed tomography scan of the upper portion of the cervical spine, showing widening of the cartilaginous space between the ossiculum terminale and the odontoid process on the left side. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

6. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

7. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

8. Three-dimensional computed tomography scan of the upper portion of the cervical spine, made after halo-brace immobilization for five months, showing that the separation between the ossiculum terminale and the odontoid had increased. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

9. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

10. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.

11. Three-dimensional computed tomography scan of the upper portion of the cervical spine, made more than six years after the initial injury, demonstrating the formation of an os odontoideum. Eiji Wada et al. J Bone Joint Surg Am 2009;91:1750-1754 ©2009 by The Journal of Bone and Joint Surgery, Inc.