Cleidocranial Dysplasia

Definition: Disorder of the bone with characteristic dental and clavicular abnormalities.

Etiology: Autosomal Dominant. 40% of cases spontaneous mutation.

- Defect in the CBFA1 gene of chromosome 6p21.

o CBFA1 gene guides osteoblastic differentiation and appropriate bone formation.

Frequency: Rare - 1: 1,000,000

Clinical features:

- Clavicles: Absence or hypoplasia of clavicles, either unilateral or bilateral

o hypermobility of the shoulders including ability to touch the shoulders together in front of the chest.

- Characteristic appearance: Short stature, large heads with frontal and parietal bossing, ocular hypertelorism, broad base of the nose, depressed nasal bridge

- Skull: Soft spot above the head, where sutures and fontanels failed to close

- Dental: Narrow and high-arched palate, increased prevalence of cleft palate, prolonged retention of deciduous teeth, delayed eruption of permanent teeth due to impacted supernumerary teeth, increased prevalence of osseous malformations

- Jaw: as individuals age, short lower face height, acute gonial angle, anterior inclination of the mandible, and mandibular prognathism develop.

o Due to inadequate vertical growth of the maxilla and hypoplastic alveolar ridge development caused by delay or lack of eruption of permanent teeth.

Treatment:

- Bone abnormalities: no treatment

- Dental abnormalities: full-mouth extractions with denture construction, autotransplantation of selected impacted teeth followed by prosthetic restoration, or removal of primary and supernumerary teeth followed by exposure of permanent teeth that are subsequently extruded orthodontically.