Anomalies of the odontoid process discovered as incidental findings on cephalometric radiographs.

Two patients with unusual developmental anomalies of the odontoid process of the axis are presented. These anomalies were discovered as incidental findings on the cephalometric radiographs obtained as part of orthodontic treatment. Both patients had severe instability of the cervical spine at the articulation between the first and second cervical vertebrae that required referral to a medical specialist. When this was discovered, both patients were asymptomatic, with normal neurologic findings. Surgical stabilization of the spine was considered but deferred because the patients had no neurologic signs or symptoms. To protect them from head injury, the patients were advised to refrain from contact sports and strenuous exercise, and follow-up evaluations were recommended. These cases emphasize the need to evaluate head and neck structures shown on cephalometric radiographs, independent of the traditional morphometric analysis.