[X-ray changes in persons with facial skeleton deformities of the "long face" type].

The analysis of X-ray data suggested that the syndrome of "long face" could be caused by three types of changes: (1), preferential lengthening of lower jaw bone; (2), combination of lower micrognathia with increased vertical dimensions of middle facial zone; (3), prevailing anterior extension of the middle facial zone. In all the three groups the vertical dimensions of the chin region of mandible were frequently enlarged.