Improvement on Mandibular Ramus Repositioning System of External Fragments in Sagittal Split Ramus Osteotomy

Part 1 System and Clinical Experience

Abstract

In sagittal split ramus osteotomy, positioning and fixation of external fragments influences on relapse or temporo-mandibular-joint (TMJ) function. We take a line to keep preoperative TMJ positions, if we observe no sign of TMJ clinically and roentogenographically. Then we established external fragment repositioning system making use of “Würzburg sagittal split system” and ready-made facebow and double buccal tubes for orthodontic treatments. This system requires no special instruments, materials and complex laboworks, do not elongates operation time too much to interfere the manipulations, and realizes sure and exact reposition of external fragment. From July 1990 to November 1991, we applied this system to 26 cases of mandibular prognathism or skeletal open bite, and obtained good clinical results.