Effect of perioperative buccal fracture of the proximal segment on postoperative stability after sagittal split ramus osteotomy

OBJECTIVES: Buccal fracture of the mandibular proximal bone segment during bilateral sagittal split ramus osteotomy (SSRO) reduces the postoperative stability. The primary aim of this study is to evaluate the effect of this type of fracture on bone healing and postoperative stability after mandibular setback surgery. MATERIALS AND METHODS: Ten patients who experienced buccal fracture during SSRO for mandibular setback movement were evaluated. We measured the amount of bone generation on a computed tomography scan, using an image analysis program, and compared the buccal fracture side to the opposite side in each patient. To investigate the effect on postoperative stability, we measured the postoperative relapse in lateral cephalograms, immediately following and six months after the surgery. The control group consisted of ten randomly-selected patients having a similar amount of set-back without buccal fracture. RESULTS: Less bone generation was observed on the buccal fracture side compared with the opposite side (P<0.05). However, there was no significant difference in anterior-posterior postoperative relapse between the group with buccal fracture and the control group. The increased mandibular plane angle and anterior facial height after the surgery in the group with buccal fracture manifested as a postoperative clockwise rotation of the mandible. CONCLUSION: Bone generation was delayed compared to the opposite side. However, postoperative stability in the anterior-posterior direction could be maintained with rigid fixation.

Three Dimensional Study on the Postoperative Stability after Advancement of Maxilla Using Le Fort I Osteotomy

0.05). In transverse plane, the distance between S1-S0 of PNS was -3.87+/-2.37 mm, S2-S0 of PNS was -3.79+/-2.39 mm, and S1-S2 of PNS was -0.08+/-0.18 mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between S1-S0 of A-point was 3.99+/-0.86 mm, S2-S0 was 3.57+/-1.09 mm, and S1-S2 was 0.42+/-0.42 mm. There were significant differences between these data (P<0.05). In coronal plane, the distance between S1-S0 of PNS was 3.82+/-0.96 mm, S2-S0 was 3.43+/-0.91 mm, and S1-S2 was 0.39+/-0.49 mm. There were significant differences between these data (P<0.05). In transverse plane, it was estimated that PNS has no statistical postoperative stability in the same direction. In coronal plane, it was estimated that both A-point and PNS had no statistical postoperative stability (P<0.05).CONCLUSION: Clinically, the operation plan needs to take into account of the maxillary relapse.

POSTOPERATIVE STABILITY OF FIXATION WITH ABSORBABLES IN SIMULTANEOUS MAXILLOMANDIBULAR ORTHOGNATHIC SURGERY

A Study On The Postoperative Stability Of Lefort I Osteotomy In The Two-Jaw Surgery Of The Skeletal Class Iii Malocclusion Patients

PURPOSE: The purpose of this study was to evaluate the postoperative stability of LeFort I osteotomy in two-jaw surgery of class III malocclusion and to help the establishment of treatment planning in patients with a skeletal class III malocclusion future. MATERIALS AND METHODS: The lateral cephalograms of 14 patients who had been underwent two-jaw surgery via one-piece osteotomy were traced and the landmarks were identified. Repeated tracings and construction of reference planes were Comparisons were made from the immediate postoperative to late postoperative results of each landmarks on the horizontal and vertical directions. CONCLUSIONS: 1. The horizontal changes of landmark ANS, point A, PNS and Mx6Rt between immediate postoperative to late postoperative were statistically insignificant(p>0.05). 2. The vertical changes of landmark ANS, point A, PNS, Mx6Cr and Mx6Rt between immediate postoperative to late postoperative data were statistically insignificant(p>0.05). 3. The horizontal change of landmark Mx6Cr between immediate postoperative to late postoperative data was statistically significant(p<0.05). 4. Results showed that it was stable that one-piece LeFort I osteotomy in two-jaw surgery of skeletal class III malocclusion.

Postoperative stability and occlusal plane alternation by orthgnathic surgery of skeletal Class III malocclusion with anterior open bite / 대한치과교정학회지

The purpose of this study is to investigate the stability of counterclockwise rotation of mandible by sagittal split ramus osteotomy to correct the skeletal Class III malocclusion with anterior open bite. Twenty five skeletal Class III open bite patients(mean age 20.6 years) who were treated by the sagittal split ramus osteotomies with rigid fixation were examined in this study. Cephalometric radiographs were taken for ach patients preoperative(T1), early postoperative(T2), and late postoperative period(T3). Mean postoperative period(T3).Mean postoperative period was 8.0 months. Cephalomerric analysis was done and data from T1, T2, and T3 were analyzed statistically by paired t-test and pearson correlation analysis. The following results were obtained. 1. Mandibular plane angle decreased 2.9degrees and mandibular occlusal plane angle related to SN plane decreased 2.7degrees after orthognathic surgery(T2). At 6 months after orthgnathic surgery(T3), mandibular plane angle increased 1.0degrees, but mandibular occlusal plane angle did not changed. 2. The amount of horizontal relapse long time after orthornathic surgery(T3) was 1.6mm at B point and it was 22% of the total posterior movements. There was no vertical relapse in the anterior facial height. 3. The related factor with horizontal relapse at late postoperative period was mandibular plane angle(p<0.01). The related factors with decreasing posterior facial height were amount of mandibular setback(p<0.01), increasing of mandibular ramus height(p<0.01), and decrease of the mandibular plane angle during operation(p<.01). 4. There was no relationship between the amount of changes in mandibular occlusal plan angle during operation and the amount of relaspe after surgery.