• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.5
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• pp.537-542
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• 2008

BSSRO is most frequently operated among orthognathic surgery techniques for repairment of maxillofacial deformities. In case of patients with maxillofacial asymmetry accompanying mandibular protrusion who are operated by BSSRO, this study considers the recovering time for masticatory force of each tooth and Masseteric EMG and the adequate time enabling normal occlusion. The patients who are operated with BSSRO under general anesthesia in Dankook Dental Hospital, Department of OMS are selected for this study. The control group is devided into 2. 26 patients with facial asymmetry accompanying mandibular protrusion are selected for group 1 and their maximum voluntary bite force and masseteric EMG are measured. Group 2 is formed by volunteers with healthy dentition who are measured maximum bite force and masseteric EMG on both sides of the mouth. At the week of 3rd, 5th, 7th, 9th and 11th, Mann-Whitney U test is carried on for statistical analysis and the result is as follows. 1. Patients with mandibular protrusion showed apparently low maximum bite force and masseteric EMG than patients with normal occlusion. 2. In comparison with control group 1, Occlusal force is regained in incisors and canines at the 9th week and in premolars and molars, 11th week and masseteric EMG is regained at 11th week. 3. Comparing to normal occlusal patients, no recovery could be found in experimental group in every parts of the mouth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.4
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• pp.272-277
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• 2011

Purpose: The aim of this study was to compare the estimated blood loss and determine the change in hemoglobin depending on the combination of each orthognathic surgery. Subjects and Methods: The subjects of this study were patients who underwent orthognathic surgery among those diagnosed with a dentofaical deformity in Mok-Dong hospital, Ewha Womans University from 2002 to 2009. One hundred patients (men - 36, women - 64, mean age of $24.5{\pm}4.6$) participated in the study and were divided into four groups (group 1 - bilateral sagittal ramus osteotomy [BSSRO], group 2 - BSSRO+Genioplasty, group 3 - Lefort 1+BSSRO+genioplasty, group 4 - anterior segmental osteotomy on maxilla and mandible). A comparative study on the estimated blood loss (EBL), operation time, peri-operative changes in hemoglobin was performed using anesthesia records. The results were analyzed statistically using a Mann-Whitney U-test and Spearman's Rho test - SPSS 12.0 (SPSS Inc. Chicago, IL, USA). Results: In group 1 (BSSRO), the mean EBL, operation time and change in hemoglobin was $394.43{\pm}52.69$ ml, $184{\pm}42.33$ minutes, and 1.43, respectively, In group 2 (BSSRO+genioplasty), it was $556.32{\pm}63.42$ ml, $231{\pm}37.45$ minutes, and 1.80, respectively. In group 3 (Lefort 1+BSSRO+Genioplasty), it was $820.55{\pm}105.54$ ml, $320{\pm}15.41$ minutes, and 2.73, respectively. In group 4 (segmental osteotomy), it was $1025.39{\pm}160.21$ ml, $355{\pm}20.10$ minutes, and 3.33, respectively. In particular, in group 3, significant differences were observed depending on the method of the orthognathic surgery. The mean EBL in a Lefort 1 osteotomy with advancement was only 687 ml, whereas Lefort 1 osteotomy with canting correction (992 ml), even impaction (764 ml), and posterior nasal spine impaction (100 ml) showed a much higher EBL. Conclusion: From these results, the EBL and peri-operation hemoglobin increased as treatment plans became more complicated and increasing operation time. Safe orthognathic surgery should be performed by applying proper autologous transfusion plans based on the average EBL of each orthognathic surgery type.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.31 no.4
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• pp.294-305
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• 2009

Purpose: This retrospective study evaluated the changes in hyoid bone and tongue positions as well as oral cavity volume after mandibular setback by BSSRO. Materials and Methods: 18 Koreans who underwent BSSRO to correct mandibular prognathism were studied. Lateral cephalograms were taken and traced preoperatively (T0), immediately (T1) and approximately 6 months postoperatively (T2). Submentovertex radiograghs were taken and traced before surgery (T0) and about 6 months after surgery (T2). The area and volume of oral cavity, the vertical and horizontal dimensions of the hyoid bone and tongue dorsum were measured. Results: Mandibular setback surgery resulted in a significant reduction of lower oral cavity volume. The hyoid bone displaced posteroinferiorly immediately after surgery, and it tended to return to its original vertical position at 6 month after mandibular setback by BSSRO. The retropalatal space around tongue was maintained and the retrolingual space around tongue was reduced immediately postoperatively. The readaptation of tongue was not evident for that the follow up period was not long enough. No significant statistical correlations between the amounts of mandibular setback and the changes of oral cavity volume were observed. Conclusion: Mandibular setback surgery resulted in a significant reduction of lower oral cavity volume, which was most likely attributable to the posterior movement of the mandible. More subjects and long-term observations should be performed to assess the changes of oropharyngeal configuration following mandibular setback surgery.

• The Journal of the Korean dental association
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• v.55 no.8
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• pp.537-540
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• 2017

BSSRO (bilateral sagittal split ramus osteotomy) is frequently performed to correct dentofacial deformity and malocclusion. Among its complications the incidence of post-operative facial nerve palsy is very rare, but it is one of the most serious complications. The case of a 21-year-old male patient who underwent facial nerve palsy after BSSRO is described. After surgical intervention and conservative therapy, the patient recovered his facial nerve function successfully.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.34 no.2
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• pp.207-215
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• 2008

Patients who have repaired cleft lip and palate generally undergo restriction of maxillary growth. Concave facial profile is often exhibited with relatively normalized mandible. Horizontal and sagittal deficiency of the maxilla could cause anterior and posterior crossbites. In growing patients, ortho-dontic and orthopedic treatment is acceptable with maxillary expansion and protraction. However, surgical approach has to be accompanied with orthodontic treatment in skeletally matured patients. We used SARPE and BSSRO to expand the constricted maxilla and retract the mandible in a patient who had cleft palate repaired in infancy. Through SARPE, orthodontic treatment and BSSRO, we sufficiently expanded the maxillla and improved facial profile.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.3
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• pp.232-240
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• 2008

Purpose: This study was performed to evaluate transverse changes of proximal segment after bilateral sagittal split ramus osteotomy (BSSRO) using 3-D CT in mandibular prognathism. Patients and methods: Twenty-two patients who underwent BSSRO for mandibular set-back in class III malocclusion without facial asymmetry were examined. Miniplates were used for the fixation after BSSRO. Facial CT was taken before and after BSSRO within 3 months. Frontal-ramal inclination (FRI), inter-gonial width (IGW) and intercondylar width (ICW) were measured in 3-D CT images using V-works $4.0^{TM}$ program. Student t-test was used to compare the changes between pre- and post-operative measurements using SPSS 10.0 program. Results: 1. Mean peroperative FRI value ($12.87{\pm}3.43^{\circ}$) was slightly increased to postoperative value ($14.13{\pm}3.72^{\circ}$) (p < 0.05). The average FRI increased 10.42% and the range was from $-2.46^{\circ}$ to $3.34^{\circ}$. 2. Mean peroperative IGW ($99.01{\pm}5.36$) was slightly decreased to postoperative IGW ($96.51{\pm}5.88mm$) (p < 0.05). The average IGW decreased 2.52 % and the range was from $-6.61^{\circ}$ to 0.91 mm. 3. Mean preoperative ICW ($125.01{\pm}5.30mm$) was slightly decreased to postoperative ICW ($125.40{\pm}5.45mm$) (p < 0.05). There is no significant difference between pre- and post-operative ICW. 4. There was significant correlationship between FRI difference and IGW difference (p < 0.05). Conclusions: These results indicate that the lower ramus of the proximal segment is moved inward after BSSRO procedure for mandibular set-back.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.141-148
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• 2010

The bilateral sagittal split ramus osteotomy (BSSRO) is preferred method of surgical correction for mandibular prognathism, retrognathism and asymmetry. This technique performed from primarily an intraoral incision to avoid a scar. After forward movement of the distal segment of the mandible, healing of bone by primary or secondary intention is easily accomplished through large areas of cancellous bony overlap. When rigid fixation is used for the BSSRO, it is possible to open the mouth during the immediate post-operative period because it promotes the healing process. Although this surgical procedure has been well-documented, the incidence of postoperative trigeminal neurosensory disorder in the region of the inferior alveolar nerve and the mental nerve remains one of the major complication. However, evaluation of objective methods for sensory recovery patterns is insufficient although most patients find their sensory return. Neurometer electrodiagnostic device performs automated neuroselective sensory nerve conduction threshold evaluation by determining current perception threshold (CPT) measures. The purpose of this study was to evaluate the sensory recovery patterns of inferior alveolar and mental nerve over time. Nerve examination with a neurometer was performed in 30 patients undergoing the BSSRO at pre-operative, post-operative 1-, 2-, 4- week, and 2-, 3-, 4-, 5-, 6- month follow-up visits after the osteotomy to compare the differences of nerve injury and recovery patterns after the BSSRO with or without genioplasty and sensory recovery patterns associated with the kind of nerve fiber.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.6
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• pp.404-412
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• 2012

Purpose: The purpose of this study was to evaluate postsurgical facial hard tissue stability after orthognathic surgery with/without posterior impaction in skeletal class III malocclusion patients, and to evaluate the horizontal relapse tendency, according to changes in anteroposterior discrepancy and occlusal planes. Methods: Ninety patients, who had undergone orthognathic surgery in Pusan National University Dental Hospital, were enrolled in this study. Three main groups were classified as follows: Thirty patients underwent mandibular setback bilateral sagittal split ramus osteotomy (BSSRO) only (BSSRO group, BG); another thirty patients underwent mandibular setback BSSRO and Le Fort I osteotomy with posterior impaction (posterior impaction group, PG); and another thirty patients underwent mandibular setback BSSRO and Le Fort I osteotomy without posterior impaction (non-posterior impaction group, NPG). Preoperative (T0), immediate postoperative (T1) and six-month follow-up period (T2) lateral cephalograms were taken, and various parameters were measured. The analyses were done by linear and angular measurements between T0-T1 and T1-T2, to evaluate postsurgical facial hard tissue stability. Results: Mean horizontal relapse rates were distributed from 11.81% to 19.08%, and there were significant postsurgical changes (0.52 mm~2.44 mm) at the B point in all 3 groups. But, there were no statistical differences on relapse rate among BG, PG and NPG patients. Conclusion: In this study, the postsurgical stabilities of BSSRO and Le Fort I osteotomy with/without posterior impaction in skeletal class III malocclusion patients were acceptable. There were no significant statistical differences in mandibular stability according to changes in anteroposterior discrepancy and occlusal planes.

• Journal of Dental Rehabilitation and Applied Science
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• v.22 no.4
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• pp.289-300
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• 2006

This study was performed to investigate the influence of orthognathic surgery on the temporomandibular dysfunction in skeletal class III malocclusion. The temporomandibular joint status in 22 patients(mean age: 23.7 years) who received orthognathic surgery such as mandibular BSSRO(14 patients), maxillary Le Fort I osteotomy with mandibular BSSRO(8 patients) was evaluated by craniomandibular index. All these patients received orthognathic surgery at least 6 months ago. The mean score and standard deviation was obtained and compared with that of 22 normal individuals(mean age: 24.8years) by Student's t-test. In mandibular movement, the score of orthognathic surgery group was higher than that of the normal group. All the items except mandibular movement did not show any differences between the two groups.

• The Journal of the Korean dental association
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• v.44 no.2 s.441
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• pp.133-138
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• 2006

This is a report of one case about facial asymmetry involving maxilla & mandible. Le Fort I Maxillary Osteotomy & BSSRO is usually used for facial asymmetry patient involving maxilla & mandible. But Le Fort I Maxillary Osteotomy has demerits about more aggressive technique, more operation times, more discomforts of post operation nasal breathing than Unilateral maxillary Segmental Osteotomy. So we treated one patient successfully using Unilateral Maxillary Segmental Osteotomy, BSSRO & Post - Operation Rapid Orthodontics instead of Le Fort I Maxillary Osteotomy.