[The morphology of the base of the cranium in prognathism. A cephalometric study of adult patients].

The cranial base of 60 adults affected by mandibular prognathism was studied with the aid of a computerized cephalometric analysis. The means and standard deviations of the values measured on the sample where compared with the cephalometric standards of the University of Michigan. The studied sample showed a significant reduction in length of the floor of the anterior cranial fossa, the cranial base angle showed no deviation from the control but the whole cranial base was backward and upward rotated in relation to the Frankfurt plane. The cranial base morphology was similar in patients with or without maxillary retrusion. The data in our possession may indicate that mid-facial sagittal growth in patients affected by mandibular prognathism is somehow impaired by altered cranial base growth. In any case the sagittal projection of the frontal and nasal bones appears to be reduced in our patients and this data must be kept in mind when studying these patients with the aid of cephalometry.