sagittal split ramus osteotomy. The complications reported in the included studies were scarce, but curved ostectomies may be able to induce many complications. The prominent mandibular angle must be analyzed in the lateral dimension and frontal dimension, and curved ostectomy can reduce the mandibular angle laterally while lateral cortical ostectomy can reduce the bigonial distance frontally. Because curved ostectomies can induce complications and unnaturally large mandibular angle while can not reduce bigonial distance efficiently, the current trend for the angle reduction procedure is lateral cortical ostectomies.]]>
Mandible ; Osteotomy, Sagittal Split Ramus

sagittal split ramus osteotomy for mandibular setback in 15 patients by paired t-test. We used oblique transcranial radiographs taken before operation and immediate after operation. And we concluded as follows; 1. The joint spaces changed under 0.2mm were 21.2%, 0.2mm to 1.0mm were 67.7%, above 1.0mm were 11.1%. 2. The mean changes of AJS, SJS, PJS were all increased and SJS was most changed of them, but there is no statistically significant change in SJS. 3. Comparing the preop. measurements with the postop. ones, there is no statistically significant changes in over all joint spaces (P> 0.05)]]>
Humans ; Joints ; Osteotomy, Sagittal Split Ramus

sagittal split ramus osteotomy.METHODS: Thirty patients with class III dental and skeletal malocclusion and who were treated with BSSRO were reviewed. Three plain radiographs such as the panoramic view, the lateral cephalogram and the submentovertex view were taken before and after operation. Also, paper surgery for STO and model surgery were used to evaluate the amount of mandibular set back.RESULTS: On the panoramic view, the amount of mandibular set back in STO was similar to the postoperative results of model surgery, but the amount of mandibular set back on the lateral cephalogram was smaller than the postoperative result of model surgery and then the amount of set back on submentovertex view was similar to the postoperative result of model surgery.CONCLUSION: Precise tracing and paper surgery should be performed for a combined expected STO in order to predict the exact amount of preoperative mandibular set back.]]>
Humans ; Jaw ; Malocclusion ; Osteotomy, Sagittal Split Ramus

OBJECTIVES: To evaluate the influence of the type of osteotomy in the inferior aspect of the mandible on the mechanical performance. MATERIALS AND METHODS: The study was performed on 20 polyurethane hemimandibles. A sagittal split ramus osteotomy (SSRO) was designed in 10 hemimandibles (group 1) with a vertical osteotomy in the buccal side (second molar level) and final osteotomy was performed horizontally on the lingual aspect, while the mandible body osteotomy was finalized as a straight osteotomy in the basilar area, perpendicular to the body. For group 2, the same osteotomy technique was used, but an oblique osteotomy was done in the basilar aspect of the mandibular body, forming continuity with the sagittal cut in the basilar area. Using a surgical guide, osteosynthesis was performed with bicortical screws using an inverted L scheme. In both groups vertical compression tests were performed with a linear load of 1 mm/min on the central fossa of the first molar and tests were done with models made from photoelastic resin. Data were analyzed using Student's t-test, establishing a statistical significance when P <0.05. RESULTS: A statistical difference was not observed in the maximum displacements obtained in the two osteotomies (P <0.05). In the extensiometric analysis, statistically significant differences were identified only in the middle screw of the fixation. The photoelastic resin models showed force dissipation towards the inferior aspect of the mandible in both SSRO models. CONCLUSION: We found that osteotomy of the inferior aspect did not influence the mechanical performance for osteosynthesis with an inverted L system.
Mandible ; Mandibular Osteotomy ; Molar ; Osteotomy ; Osteotomy, Sagittal Split Ramus* ; Polyurethanes

OBJECTIVE: Autologous transfusion is frequently used with orthognathic surgery. The necessity of autologous transfusion has begun to question alone in bilateral sagittal split ramus osteotomy. The aim of this study was to evaluate the availability of autologous transfusion. METHODS: The chart reviews of sixty patients who had undergone bilateral sagittal ramus osteotomy were done. The subjects were divided into two groups : In experimental group, 30 patients who autodonated 320ml in the preoperative 3 weeks actually received a transfusion in the postoperative 6 hours were included. In control group, 30 patients who underwent the same operation without preoperative donation and any other transfusion were included. Hemoglobin, hematocrit, and changes of these values in both groups were evaluated. RESULTS: 1. From postoperative 3 hours to postoperative 1 day, the increases of hemoglobin(0.8g/dL in experimental group, 0.2g/dL in control group) and hematocrit(0.3% in experimental group, 0.6% in control group) were not statistically significant between both groups. 2. From postoperative 1 day to postoperative 1 week, the increase of hemoglobin(0.6g/dL in experimental group, 0.3g/dL in control group) was not statistically significant between both groups. But the increase of hematocrit(2.5% in experimental group, 1.0% in control group) was statistically significant between both groups over the same period(hematocrit p=0.043). 3. On postoperative 1 week, the values of hemoglobin(12.3% in both groups) and hematocrit(35.6% in experimental group, 36.8% in control group) were not statistically significant between both groups. CONCLUSION : The autologous transfusion in surgery of just a little blood loss was not effective. The most results show that there is little availability of autologous transfusion according to changes of hemoglobin and hematocrit in bilateral sagittal split ramus osteotomy.
Hematocrit ; Humans ; Orthognathic Surgery ; Osteotomy ; Osteotomy, Sagittal Split Ramus* ; Prognathism*

Sagittal split ramus osteotomy(SSRO) has become one of the most popular procedure for correction of mandibular prognathism. Rigid fixation is favored for its stability and patient comfort. But there were few data presented about skeletal stability and factors contributing to relapse for sagittal split ramus osteotomy with rigid fixation. From August 1997 to August 2002, eleven patients, who underwent sagittal split osteotomy with rigid fixation, were studied. Patients with genioplasty or any other orthognatic surgical procedures were excluded from sample. Lateral cephalograms were analyzed before surgery, 1 month after surgery, and 12 months after surgery. The mean amount of surgical setback was 6.29 mm at pogonion and the mean amount of skeletal relapse was 1.29 mm at pogonion. The mean postoperative horizontal change of soft tissue pogonion was 5.66 mm posteriorly, vertical change of menton was 1.83 mm superiorly, and angular change of ramus inclination was 5.88 degree increased. The mean amount of postoperative movement was 1.9 mm anteriorly at soft tissue pogonion, 2.13 mm superiorly at menton, 0.8 degree was decreases at ramus inclination. The amount of skeletal relapse is related to the amount of setback. The results of this study present that the bilateral sagittal split osteotomy with rigid fixation has many advantages and stable procedure for the correction of mandibular prognathism.
Genioplasty ; Humans ; Osteotomy ; Osteotomy, Sagittal Split Ramus* ; Prognathism* ; Recurrence

osteotomy, through three-dimensional computed tomography.METHODS: We selected 14 patients who were taken postoperative three-dimensional computerized tomography at the time before surgery, immediately after surgery, six months after surgery among the patients undergone both maxillary advancement surgery using Le Fort I osteotomy and mandibular retrusive surgery using bilateral sagittal split ramus osteotomy. We measured and compared the vertical distance of A-point and posterior nasal spine (PNS), the horizontal distance of A-point and PNS in transverse plane and coronal plane of the three-dimensional reconstructed images, respectively.RESULTS: In transverse plane, the distance difference between immediately after surgery (S1) and immediately before surgery (S0) of A-point was -0.04+/-1.80 mm, S2 and S0 was -0.15+/-1.69 mm, and between S1 and S2 was 0.11+/-0.58 mm. There were no significant differences between these data (P>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.]]>
Humans ; Malocclusion ; Maxilla ; Osteotomy ; Osteotomy, Sagittal Split Ramus ; Recurrence ; Spine

OBJECTIVE: To summarize the application and recent development of orthognathic surgery in treating syndromic craniosynostosis. METHODS: The related literature at home and abroad in recent years was extensively reviewed, and the indications, routine procedures, and protocols of orthognathic surgery in the treatment of syndromic craniosynostosis were summarized and analyzed. RESULTS: Craniosynostosis is a common congenital craniofacial malformation. Syndromic craniosynostosis usually involves premature fusion of multiple cranial sutures and is associated with other deformities. Orthognathic surgery is the necessary and effective means to improve the midfacial hypoplasia and malocclusion. Le Fort I osteotomy combined with sagittal split ramus osteotomy are the common surgical options. Orthognathic surgery should combine with craniofacial surgery and neurosurgery, and a comprehensive long-term evaluation should be conducted to determine the best treatment plan. CONCLUSION Orthognathic surgery plays an important role in the comprehensive diagnosis and treatment of syndromic craniosynostosis. The development of digital technology will further promote the application and development of orthognathic surgery in the treatment of syndromic craniosynostosis.
Humans ; Orthognathic Surgery ; Craniosynostoses/surgery* ; Osteotomy ; Osteotomy, Sagittal Split Ramus

For the study of its stability when the screw has been fixed after sagittal split ramus osteotomy(SSRO) of the mandible, the methods of screw arrangement are classified into two types, triangular and straight. The angles of screws to the bone surface are classified as perpendicular arrangements, the 60degrees anterioinferior screw, known as triangular, and the most posterior screw, called straight arrangement, thus there are four types. The finite element method model has been made by using a three dimensional calculator and a supercomputer. The load directions are to the anterior teeth, premolar region, and molar region, and the bite force is 1 Kgf to each region. The distribution of stress, the von-Mises yield strength, and safety of margin refer to the total sum of transformed energy have been studied by comparison with each other. The following conclusion has been researched : 1. When shear stress is compared, in the triangular arrangement in the form of "giyeok", the anterosuperior screw is seen at contributing to the support of the bone fragment. In the straight arrangement, substantial stress is seen to be concentrated on the most posterior angled screw. 2. When the von-Mises yield strength is compared, it seemed that the stress concentration on the angled anteroinferior screw is higher, it shows a higher possibility of fracture than any other screw. In the straight arrangement, stress appeared to be concentrated on the most posteriorly angled screw. 3. When the safety margins of the transfomed energy are compared, the energy conduction is much greater in the case of the angled screw than in the case of the perpendicular screw. The triangular arrangement in the form of "giyeok" shows a superior clinical sign to that of the straight arrangement. Judging from the above results, when the screw fixation is made after SSRO in practical clinical cases, two screws should be inserted in the superior border of mandibular ramus and a third screw of mandibular inferior border should be inserted in the form of triangular. All screws on the bony surface should be placed perpendicularly-90 degrees angles apparently best promote bony support and stability.
Bicuspid ; Bite Force ; Mandible ; Molar ; Osteotomy, Sagittal Split Ramus* ; Tooth

OBJECTIVE: The purpose of the present study was to evaluate the postoperative three-dimensional (3D) changes in the proximal segments after mandibular setback sagittal split ramus osteotomy and to compare the changes between the conventional mini-plate fixation and semi-rigid sliding plate fixation. METHODS: Cone-beam computed tomography (CBCT) images were used to evaluate the postoperative 3D changes in the proximal segments during the healing process. CBCT images were superimposed using the symphysis and the lower anterior mandible as references. RESULTS: There were no statistically significant differences between the conventional mini-plate and semi-rigid sliding plate groups (p > 0.05). With respect to the distribution of changes greater than 2 mm in the landmarks, the right condylion, right coronoid process, and left condylion showed ratios of 55.6%, 50.0%, and 44.4%, respectively, in the semi-rigid sliding plate group; however, none of the landmarks showed ratios greater than 30% in the conventional mini-plate group. CONCLUSIONS: There were no statistically significant differences in postoperative changes in the segments between the conventional mini-plate and semi-rigid sliding plate groups. Nevertheless, while selecting the type of fixation technique, clinicians should consider that landmarks with greater than 2 mm changes were higher in the semi-rigid sliding plate group than in the conventional mini-plate group.
Cone-Beam Computed Tomography ; Mandible ; Osteotomy, Sagittal Split Ramus