Relation between cranial base flexure and position of the jaws.

Correlation between the cranial base flexure with the sagital and vertical positions of both jaws has been analysed on 180 radiographs of eugnathic probands and 256 radiographs of patients with various malocclusion forms. Radiographs were analysed by conventional cephalometric procedures determining maxillar rotation, mandibular rotation, sagittal position of the maxilla, sagittal position of the mandible, and cranial base flexure. A significant correlation between the degree of cranial base flexure and facial prognathism was found. The correlation coefficients were higher in eugnathic probands than in those with malocclusions. Regression analysis defined three basic types of sagittal bimaxillar relations: orthognatism, retrognatism and prognatism.