[A study of genetic influence on the cranial base variations in cases with cleidocranial dysostosis].

The purpose of the present study was an investigation of the hereditary influence on the shape and size of the cranial base in cases with cleidocranial dysostosis, in an attempt to contribute to an improved understanding of the syndrome. The sample consisted of 32 patients with cleidocranial dysostosis. Out of these 32 cases, 21 were affected members of 7 families and 11 sporadic cases. Quantitative and qualitative types of study were performed on the lateral skull radiographs. The first part of study involved a metric analysis of the angle NSBa and lengths of the anterior (N-S) and posterior (S-Ba) parts of the cranial base as well as the total length of the cranial base (N-Ba). The second part of this study involved a superimposition of the cranial base as well as its parts (pituitary fossa, anterior and posterior clinoid processus, dorsum sellae and the part of clivus facing the endocranium) in both the family and sporadic cases in order to assess the degree of similarity between them. In the first part of study a comparison was made between sample with syndrome and a control sample consisting of normal cases of adequate sex and age. Significance of differences between the samples was calculated by using t test. It was found that the sample with syndrome demonstrated significantly lower mean values of N-S, S-Ba and N-Ba dimensions. The mean value of NSBa angle was lower in the sample with syndrome but there was no significant difference. Following this, cases with the syndrome were divided in two groups: familial and sporadic.(ABSTRACT TRUNCATED AT 250 WORDS)