Jaw fixation as the key to diagnosis of fibrodysplasia ossificans progressiva.

Fibrodysplasia ossificans progressiva is a very rare and disabling hereditary disorder of connective tissue characterised by symmetric congenital anomalies of the great toes and thumbs and by progressive heterotopic ossification of tendons, ligaments, fasciae and striated muscles. In this case we report a 17-year-old boy who presented with a painful swelling of the right mandibula with trismus. Multiple heterotopic soft tissue calcifications, severe scoliosis and typical anomalies of toes and thumbs on the radiographs were pathognomonic for fibrodysplasia ossificans progressiva.