Radiographic diagnosis of Limbus vertebra on a lateral cephalometric film: report of a case.

Although Limbus vertebra is not an uncommon radiological finding in an adult, it is a rare finding in the child or adolescent. The most common site for the presence of Limbus vertebra is the mid-lumbar region and less commonly occurs in the mid cervical region. It is a defect (tiny unfused apophyseal fragment) in the anterior margin of the vertebral body usually at the superior anterior margin in the lumbar vertebrae and at the anteroinferior margin in the cervical vertebrae. These margins are the sites of epiphyseal centers on vertebrae. A case of Limbus vertebra seen on a routine lateral cephalometric radiograph taken prior to Orthodontic treatment is reported and the literature is reviewed. The Limbus vertebra is thought to result from herniation of the nucleus pulposus through the ring apophysis prior to fusion isolating a small segment of the vertebral rim. This could be mistaken for a fracture, infection or tumor resulting in further invasive diagnostic procedures. It is important to recognize that this represents the sequela of a remote injury in an immature skeleton. A sound knowledge of this anomaly is essential for all clinicians so that appropriate measures can be taken without unduly alarming patients.