A one-stage surgical correction of gnathic deformities involving both jaws is described. It permits both the establishment of a normal occlusion and correct alignment of the occlusal plane to the skull. The osteotomy commences with the mandible. Its new position is oriented to the (as yet) untouched maxilla with the aid of an intermediate occlusal splint produced as a result of cephalometric evaluation and cast model surgery. The mandible is secured at its osteotomy sites by bone screws, in the correct final position. The maxilla is then oriented to the mandible, now correctly positioned with the aid of a second, preformed occlusal splint again produced on the basis of cast model surgery. Following intermaxillary fixation and internal wire suspension the splint is left in place until bony consolidation has taken place. External fixation is not required. The procedure enables the cephalometrically established measurements for the movements of both jaws to be easily reproduced with a high degree of accuracy. The technique is described in detail and discussed on the basis of clinical examples.