Atlanto-occipital Assimilation an Incidental Cephalometric Finding: Diagnosis and Clinical Implications – A Case Report

Occipitalization of atlas is an osseous anomaly of the craniovertebral junction, which occurs at the base of the skull in the region of the foramen magnum. It is the fusion of first cervical vertebra with the occipital bone of the skull. A 16-year-old patient reported with chief complaint of irregularly placed teeth. Routine lateral cephalogram assessment revealed the presence of fusion between first cervical vertebrae (C-1) and base of skull. The radiographic investigation revealed the presence of fusion along with the clinical findings of short neck, short face, cleft palate, missing teeth, and pain during neck extension and flexion. Such cases of craniocervical anomaly can cause orthopedic and neurological problems like abnormal posture of head, restricted neck movements, cervical pain, pain in extremities, wasting of muscles, and convulsions. The comprehensive radiographic assessment of all structures visible in cephalogram of orthodontic patient can help in identification of such anomalies and sensitize the patients about symptomatic or asymptomatic condition.