Cephalometic study of dento-facial changes after orthognathic-surgical correction of mandibular prognathism.

To clarify the morphological lento-facial changes after Obwegeser-Dal Pont osteotomy, 23 cases of mandibular prognathism were analysed by means of lateral cephalometrics.The results were as follows;1) A high correlation (significant at 1% level) could be found between the horizontal relapse of the upper and the lower incisor, as well as between the horizontal relapse of the mandibular body and the upper incisor.2) No correlation was found between the skeletal feature (mandibular plane angle, A-B difference) of each case and the extent of relapse.3) A relatively high correlation was found between the displacement by surgery and relapse (significant at 5 % level) as well as between the extent of the mandibular rotation by surgery and that of relapse.It was suggested from these results that the compensatory tooth movement after surgical correction is thought to play an important role in occlusal stability.