Cleidocranial dysplasia: craniofacial morphology in adult patients.

The aim of the study was to carry out a detailed quantitative analysis of craniofacial morphology in a relatively large sample (N = 35) of adult patients with cleidocranial dysplasia (CCD) in order to contribute to the understanding of the characteristic craniofacial abnormalities. Roentgencephalometric films in the lateral, frontal, and basal projections were analyzed and mean facial diagrams for the lateral and frontal films were produced based on registration of 216 reference points. In the calvaria an increased width and a relatively more prominent frontal region were found. In the cranial base the most significant findings were reduced width, a cranial displacement of the clivus and sella, and an anteriorly facing foramen magnum. The orbital openings were high and narrow and nearly all patients had hypoplasia or aplasia of the nasal bones. The maxilla and mandible were reduced in height and width and the mandible was anteriorly inclined. It was concluded that all craniofacial regions are affected in CCD. Based on the present and previous studies, it is suggested that the abnormal craniofacial morphology in CCD may be explained by the skeletal dysplasia, combined with early cranial deformation and dysplastic and compensatory skeletal growth. Thus, the findings lead to the comprehension that several primary and secondary causal factors are involved in craniofacial morphogenesis in CCD, and that knowledge of early development is important when etiology and pathogenesis in a syndrome is searched for.