Obwegeser II method and Rigid fixation conserving the condylar position has been performed on 5 patients with severe mandibular prognathism, and we obtained the result after the follow up study follows. 1. Obwegeser II method is considered to move the distal segment passively when surgical correction of severe open bite correction and large amount of set back above 15mm is needed. 2. In one case that has more change of condylar position after operation, documented immediate postoperative relapse have been occurred 3. In the others that have adequate control of condylar position, passive set back and firm skeletal fixation, more functional and esthetic improvement and more post-operative stability has been achieved