Cleidocranial  Dysplasia

Cleidocranial Dysplasia (cleido = collar bone, + cranial = head, + dysplasia = abnormal forming) , also known as Cleidocranial Dysostosis and Marie-Sainton Disease, is a condition characterized by defective development of the cranial bones and by the complete or partial absence of the collar bones (clavicles).

It is autosomal dominant disorder.Several chromosome abnormalities have been linked with this syndrome, including chromosome 6p21.

Clinical features:-The typical individual present with large head,small face and drooping shoulders. Height is reduced.The chest is narrowed and coned shaped. Mental status normal. Gait disturbances common.Caries tooth and periodontitis is common.

Skull- Delayed and absent  ossification. Widening  of the principle sutures giving appearance of Hot Cross Bun.Marked brachycephaly with interparietal dimeter.Foramen magnum is deformed and enlarged and there  may be platybasia.

Face is small with underdeveloped facial bones and paranasal sinuses. Maxilla is small and mandible is large. Delayed and defective dentition.

Thorax-Anamolus clavicular developed is nearly constant findings.Scapulae are small and elevated.The shoulder girdles allow great mobility of the shoulders. Chest is narrow and cone shaped.

Pelvis-The bones of the pelvis are small and underdeveloped Many patients have an unusal shape of the femoral head,like chef’s hat.

Spine- The vertebrae shows biconvex vertebral bodies and spina bifida occulta.There is increased incidence of spondylolysis in the lumbar spine.Hyperlardosis,excessive kyphosis and scoliosis.

Extrimities-An accessory epiphysis for the base of the 2 nd metacarpal occurs,creating an elonged digit. The distal phlanges are hypoplastic and pointed.