Hosting 728 files, 2951 images, and 4 contributors.

Random Case

Gallbladder varices
Bradford W. Betz, MD
over 10 years ago
Enter A Workflow
Standard2   Academic2

Please choose a workflow. A standard workflow allows you to browse the repository with full case detail; the academic workflow allows you to browse the repository with limited case detail revealed. Double click on the images to launch image viewer.

ARSt Case Repository

Subdental Synchondrosis Fracture

Case Detail

Anatomy: Brain-Spine
Joseph Junewick, MD FACR
Diagnostic Category: Trauma
Created: over 10 years ago
Updated: over 10 years ago
Tags: PEDS
Modality/Study Types: CT MR
Adobe32 PDF Imagej32 ImageJA


15 month old male in motor vehicle accident.

Case Images


Subdental Synchondrosis Fracture


CT – Nondisplaced transverse fracture through the dental synchondrosis.

MR – Type 2 odontoid fracture; edema in body of the axis subjacent to the synchondrosis.


The right and left dental ossification centers are separated from the body of the axis by the subdental synchondrosis. The subdental synchondrosis usually fuses by adolescence but may variably persist into adulthood. The subdental synchondrosis is a potential weak spot and prone to hyperflexion injury. Since the sagittal fulcrum of the cervical spine is in the upper cervical region in children compared to the lower cervical region in adults, this vulnerability is potentiated. Remnants of the synchondrosis persist in upto 87% of adults and may account for the high incidence of type 2 dens fractures and poor healing (pseudoarthrosis).


Gebauer M, Lohse C, Barvencik F, et al. Subdental synchondrosis and anatomy of the axis in aging: A histomorphometric study in 30 autopsy cases. Eur Spine J (2006); 15:292-298.

Corporate Office: 616.363.7272, 3264 North Evergreen Drive, Grand Rapids, MI 49525

Spectrum Health Helen Devos Childrens Hospital GE HealthCare