Stability Of Two-Jaw Surgery And Single Mandibular Surgery In Mandibular Prognathism

Park, Jae Wan; Lee, Eun Taek; Min, Seung Ki; Lee, Dong Keun

Abstract

Le-Fort I Osteotomy is considered by many surgeons to be a safe and predictable method for correcting various dentofacial deformities. However, there are controversial options concerning the stability of two-jaw surgery (Le-Fort I osteotomy and sagittal split ramus osteotomy)compared to single mandibular surgery (sagittal split ramus osteotomy). The purpose of this study was to evaluate the post-operative stability of mandible in two-jaw surgery and single mandibular surgery, to help the establishment of accurate treatment planning in patients with a skeletal class III malocclusion. There were 15 patients who had been undergone two-jaw surgery and 20 patients who had been undergone single mandibular surgery.Lateral cephalograms of these 2groups ;Preoperation and immediate postoperation, postoperatively 1month, postoperatively 3 months, at the latest follow up(>6months); were analyzed by linear measurement to evaluate changes in position (hard tissue B, Pogonion point)and compare relapse both group.The results obtained were as follows ; In view of B-point, the horizontal relapse rate of single mandibular surgery was 10.17%at post-op 1month,12.52%at post-op 3months,13.01%at post-op 6months and two-jaw surgery was 10.23%at post-op 1month,11.84% at post-op 3months,12.97%at post-op 6months. the horizontal relapse rates of Pogonion point were 10.78% at post-op 1month,12.21% at post-op 3months,12.98%at post-op 6months in single mandibular surgery and those were 10.27%at post-op 1month,11.33% at post-op 3months, 12.01%at post-op 6months in two-jaw surgery. In terms of vertical relapse rate, rates of B point were 22.96%at post-op 1month,28.30%at post-op 3months,29.56%at post-op 6months in single mandibular surgery and 21.14%at post-op 1month, 25.45% at post-op 3months,28.86% at post-op 6months in two-jaw surgery.Those of Pogonion point were 26.63%at post-op 1month,28.40% at post-op 3months,29.29% at post-op 6months in single mandibular surgery and 20.20%at post-op 1 month, 25.44% at post-op 3 months, 27.68% at post-op 6months in two-jaw surgery. There were no statistical difference between single mandibular surgery and two-jaw surgery in mandibular stability.