• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제33권5호
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• pp.524-529
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• 2007

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.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권4호
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• pp.229-239
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• 2009

The purpose of this study is to evaluate the change in condylar position, width, and angle before and after orthognathic surgery using 3-dimensional computed tomograph. Pre and posterative 3-D CT was taken on 38 patients and through axial, frontal, sagittal measurements and by 3-dimensional reconstruction, the changes in condylar postion, mandibular width and angle were analyzed and others such as the difference in gender, operation and fixation method, setback length and in relation with temporomandibular disorders were done together too. The results were as follows: The inward rotation of condyle in axial condylar angle, the forward movement of right condyle in sagittal anterior-posterior distance, the superior movement of both condyles in sagittal superior-inferior distance, the decrease in gonial angle, the increase in mandibular width, the decrease in distance between the axial coronoid process distance and the increase in the frontal intercondylar distance were statistically significant. There were no statistically significant changes in gender difference, however in the difference in operation method, change in the gonial angle was observed and there was more change in bilateral sagittal split osteotomy group compared to two-jaw surgery group. In the difference in fixation method, the decrease in axial coronoid process distance and the change in sagittal anterior-posterior distance were statistically significant. In the difference in setback, the increase in setback didn't relate directly with the increased change in condyle position. In the relation with temporomandibular disorder, changes in left axial condylar angle and axial coronoid process distance were statistically significant. Changes in condylar position could be observed after the orthognathic surgery but it doesn't seem to have much of a clinical importance. The orthognathic surgery is effective in decreasing the mandibular angle, and it is not related with the temporomandibular disorder.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제31권6호
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• pp.485-491
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• 2009

Postoperative skeletal stability was evaluated in combination of Le Fort I and U-shaped osteotomies for superior repositioning of maxilla in bi-maxillary surgeries in 30 consecutive patients. The fifteen patients underwent Le Fort I osteotomy alone and the other fifteen patients underwent Le Fort I and U-shaped osteotomies. In all patients, the maxilla was first osteomized and fixed with absorbable plates system. A bilateral sagittal split ramus osteotomy (BSSRO) of the mandible was then carried out and fixation was performed using absorbable plates. Maxillo-mandibular fixation with rubber ring was used for two weeks post-operatively in all patients. Lateral cephalograms were obtained pre-operatively, 1 day post-operatively, 6 months after surgery. The changes in anterior nasal spine (ANS), point A, upper incisior (U1), and point of maxillary tuberosity (PMT) were examined. The maxillas in the fifteen patients of both examination group were repositioned nearly in their planned positions during surgery and no significant post-operative changes in the examined points of the maxilla were found. These results suggest that a combination of a Le Fort I and U-shaped osteotomy is a useful technique for reliable superior repositioning of the maxilla. The post-operative change in the maxilla using this combination osteotomy was comparatively stable.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제37권
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• pp.36.1-36.7
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• 2015

Background: This study was performed to evaluate three-dimensional positional change of the condyle using three-dimensional computed tomography (3D-CT) following unilateral sagittal split ramus osteotomy (USSRO) in patients with mandibular prognathism. Methods: This study examined two patients exhibiting skeletal class III malocclusion with facial asymmetry who underwent USSRO for a mandibular setback. 3D-CT was performed before surgery, immediately after surgery, and 6 months postoperatively. After creating 3D-CT images by using the In-vivo $5^{TM}$ program, the axial plane, coronal plane, and sagittal plane were configured. Three-dimensional positional changes from each plane to the condyle, axial condylar head axis angle (AHA), axial condylar head position (AHP), frontal condylar head axis angle (FHA), frontal condylar head position (FHP), sagittal condylar head axis angle (SHA), and sagittal condylar head position (SHP) of the two patients were measured before surgery, immediately after surgery, and 6 months postoperatively. Results: In the first patient, medial rotation of the operated condyle in AHA and anterior rotation in SHA were observed. There were no significant changes after surgery in AHP, FHP, and SHP after surgery. In the second patient, medial rotation of the operated condyle in AHA and lateral rotation of the operated condyle in FHA were observed. There were no significant changes in AHP, FHP, and SHP postoperatively. This indicates that in USSRO, postoperative movement of the condylar head is insignificant; however, medial rotation of the condylar head is possible. Although three-dimensional changes were observed, these were not clinically significant. Conclusions: The results of this study suggest that although three-dimensional changes in condylar head position are observed in patients post SSRO, there are no significant changes that would clinically affect the patient.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권4호
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• pp.411-419
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• 2000

Purpose: This study was aimed at analysis of the changes in the condyle position in subjects with mandibular setback osteotomies Method: Twenty patients were evaluated retrospectively for their changes in the condyle position who underwent surgical mandibular setback using bilateral sagittal split osteotomies with a manual condyle repositioning technique and rigid fixation. The cephalometric and panoramic analysis was performed preoperatively, 1 week, 6 months, and 1 year postoperatively. And postoperative noise, temporomandibular joint pain, and mouth opening were clinically examined 2 months, 4 months, 6 months, 8 months, 10 months, and 12 months postoperatively. Result: The condyles rotated posteriorly and laterally immediately after surgery, and they returned to the preoperative position during follow-up period but it is not significant. The statistical analysis (Paired t-test) showed no significant effects in postsurgical stability. The changes in the condyle position didn't have a significant harmful influence on temporomandibular joint disorder. Conclusion: A careful surgical mandibular setback using manual condyle repositioning and fixation technique will move condyle minimally and that will decrease the relapse and temporomandibular joint disorder.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권4호
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• pp.169-172
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• 2014

Objectives: The purpose of this retrospective study was to compare the amount of postoperative drainage via closed suction drainage system after intraoral vertical ramus osteotomy (IVRO) and sagittal split ramus osteotomy (SSRO). Materials and Methods: We planned a retrospective cohort study of 40 patients selected from a larger group who underwent orthognathic surgery from 2007 to 2013. Mean age (range) was 23.95 (16 to 35) years. Patients who underwent bilateral IVRO or SSRO were categorized into group I or group II, respectively, and each group consisted of 20 patients. Closed suction drainage system was inserted in mandibular osteotomy sites to decrease swelling and dead space, and records of drainage amount were collected. The data were compared and analyzed with independent t-test. Results: The closed suction drainage system was removed at 32 hours postoperatively, and the amount of drainage was recorded every 8 hours. In group I, the mean amount of drainage was 79.42 mL in total, with 31.20 mL, 19.90 mL, 13.90 mL, 9.47 mL, and 4.95 mL measured at 0, 8, 16, 24, and 32 hours postoperatively, respectively. In group II, the mean total amount of drainage was 90.11 mL, with 30.25 mL, 25.75 mL, 19.70 mL, 8.50 mL, and 5.91 mL measured at 0, 8, 16, 24, and 32 hours postoperatively, respectively. Total amount of drainage from group I was less than group II, but there was no statistically significant difference between the two groups (P=0.338). There was a significant difference in drainage between group I and group II only at 16 hours postoperatively (P=0.029). Conclusion: IVRO and SSRO have different osteotomy design and different extent of medullary exposure; however, our results reveal that there is no remarkable difference in postoperative drainage of blood and exudate.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제28권3호
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• pp.196-204
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• 2002

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 $60^{\circ}$ 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 "ㄱ", 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 "ㄱ" 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-$90^{\circ}$ angles apparently best promote bony support and stability.

• Journal of Korean Dental Science
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• 제14권2호
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• pp.110-117
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• 2021

Purpose: The purpose of this article is to study the relationship of unintentionally extended split in the distal segment during the bilateral sagittal split ramus osteotomy (BSSRO) and skeletal relapse. Materials and Methods: Twenty patients with mandibular prognathism were divided into two groups according to whether or not unintentionally extended split had occurred. Cone-beam computed tomography images were taken before surgery (T0), immediately after surgery (T1), and postoperatively at 6 months (T2). The stability was evaluated by measuring the change of Nasion perpendicular-Pogonion (N-Pog) distance. Result: Both groups showed mild advancement of Pog during follow-up. In both groups, the condyle head rotated inward and moved posterioinferiorly after surgery, but tended to return to their original position during follow-up. Conclusion: There was no statistically significant difference between the two groups in mandible position. Moreover, the condylar position was stable. If it is difficult to proceed reduction of the unintentionally extended split, careful inspection should be performed to prevent subsequent complications during follow-up.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제42권
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• pp.41.1-41.11
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• 2020

Background: Orthognathic surgery such as bilateral sagittal split ramus osteotomy (BSSRO) for the treatment of mandibular deformities is one of the most common procedures in maxillofacial operations that may lead to neurosensory disturbance. In this study, we aimed to evaluate the effectiveness of low-level laser therapy (LLLT) on augmenting recovery of neurosensory disturbance of inferior alveolar nerve (IAN) in patients who underwent BSSRO surgery. Methods: A comprehensive literature search was conducted by two independent authors in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), Scopus, Embase, and Google Scholar electronic databases. Besides, a manual search of all textbooks and relevant articles were conducted. Searches took place in August 2020 and were limited to published and peer-reviewed articles from 2000 to 2020. All analysis was performed using the comprehensive meta-analysis (CMA) and the STATA MP (version:16) software. The weighted mean difference (WMD) using the inverse variance method and the standard mean difference (SMD) was considered for continuous variables. Results: Seventy-four papers were retrieved after removing duplicate studies and finally, eight studies were assessed for qualitative synthesis and five for meta-analysis. Totally, 94 patients were included in the meta-analysis. Based on the meta-analysis, it was shown that LLLT was not effective in a short interval (0 to 48 h) after surgery, but in a period of more than 1 month after surgery, the positive results of treatment can be observed strikingly. Also, LLLT side/group showed no significant difference in some aspects of neurosensory recovery such as thermal sensation compared to the placebo side/group. Conclusions: The meta-analysis of randomized controlled trials revealed that LLLT generally improves IAN sensory disturbance caused by BSSRO. Further high-quality clinical trials with longer follow-up periods and larger sample sizes are recommended.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권1호
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• pp.26-34
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• 2003

Intraoral Vertical Ramus Osteotomy,along with Sagittal Split Ramus Osteotomy,is an popular surgical technique performed on mandibular prognathism. However Intraoral Vertical Ramus Osteotomy has been suspected for an initial mobilization at the healing phase of segment because it does not employ the rigid fixation between segments. To execute a study on the healing phase of segment after Intraoral Vertical Ramus Osteotomy on the horizontal plane, 102 patients (204 parts) who were diagnosed mandibular prognathism and took Intraoral Vertical Ramus Osteotomy at the Yonsei University dental hospital were observed during the period of before operation, immediately postoperation, 1 month, 3 months, 6 months, and 12 months. The change in the width of segment and horizontal angle of proximal segment and condylar head on the Submentovertex Cephalogram taken from those patients represented following results. 1. The width of proximal and distal segment decreased with the lapse of time. It decreased into 84.5% between immediate postoperative and 6M and even continued to decrease till 12M. 2. The horizontal angle of the proximal segment did medial rotation according as the lapse of time and rigorously continued till 3M. The rotation angle of condylar head indicated its tendency of recurrence to the original position but the entire recurrence was not allowed. The bigger an initial angle was, the higher was the tendency of recurrence after the operation while the rotation angle remained still bigger. 3. After grouping into group 1, group 2,and group 3 based on the extent of the variation of rotation angle of condylar head at immediate postoperative, the variation of rotation angle was measures in each group. The result presented that the initial rotation angle of condylar head had correlation with that of proximal segment but had no relation with the extent of setback of the mandible. However a quantitative analysis alone is not a sufficient method for analyzing the healing phase of segment on the horizontal plane.Therefore a multilateral analysis using 3 dimensional data such as CT is recommendable for the future study.