Cleidocranial dysplasia: Radiological mimic of pyknodysostosis - A case report.

Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal disorder with predominant membranous bone involvement. It may also occur as a sporadic mutation. The diagnosis of this condition is based on the clinical, radiological and genetic findings. It is characterised by hypoplasia or aplasia of the lateral thirds of the clavicles; craniofacial and dental anomalies; and hypoplastic iliac bones. Pyknodysostosis is a close radiological mimic of this entity. Definite diagnosis is based on the genetic analysis. A 36-year-old short-statured female was referred for computed tomography of the paranasal regions for complaints of a deviated nasal septum and midline depression in her forehead. Skeletal screening demonstrated an open metopic suture, wormian bones, maxillary hypoplasia, maldentition and aplastic lateral thirds of both clavicles. In this article, we report a case of CCD, discuss various overlapping features between CCD and pyknodysostosis and attempt to differentiate them radiologically.