• Maxillofacial Plastic and Reconstructive Surgery
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• v.35 no.4
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• pp.211-220
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• 2013

Purpose: The purpose of this study was to compare the changes in the pharyngeal airway space, tongue and hyoid bone positions according to the orthognathic surgical methods of mandibular prognathism. Methods: The subjects included 30 patients (16 males, 14 females) with the skeletal class III malocclusion. Group 1 (10 patients) underwent bilateral sagittal split ramus osteotomy (BSSRO) only; group 2 (10 patients) underwent BSSRO with genioplasty; and group 3 (10 patients) underwent BSSRO, Le Fort I osteotomy. We measured the lines between the selected upper air way, hyoid bone and tongue landmarks on the lateral cephalometric x-ray films of skeletal class III. The measurements were made preoperation, within 1 week after the operation, 3~6 months after the operation and 1 year after the operation. We compared and analyzed the measurements with matched paired t-test and independent samples t-test. Results: There were no postoperative changes in the nasopharyngeal airway space in group 3. The measurements of group 3 also increased during the follow-up period as compared to the preoperative measurements. In group 1, 2 and 3, the immediate postoperative oropharyngeal and hypopharyngeal airway spaces were decreased. In the following period, the hypopharyngeal airway space returned to the preoperative positions, but the oropharyngeal airway space was not significantly changed. The upper and lower tongue was posteriorly repositioned immediately after the surgery. During the follow-up period, the lower tongue position returned to the preoperative position, and the upper tongue position was not significantly changed. Immediately after the surgery, the B point was moved to the posterior position, and a slight anterior advancement was found in the follow-up period. Conclusion: Patients who received the mandibular setback surgery showed a decrease in the posterior airway space, and those who underwent maxillary advancement showed a significant increase of the nasopharyngeal airway space, which remained stable during the evaluation period. The change of the airway space, position of the hyoid bone and tongue did not differ according to the presence or absence of genioplasty.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.2
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• pp.100-105
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• 2012

Purpose: In general, the surgical treatment for mandibular retrognathism is represented by two methods, distraction osteogenesis (DO) and mandibular osteotomy surgery. The DO is mostly preferred when the degree of advancement of mandible is large. However, the postoperative stability of mandibular advancement using DO have not been actively investigated. Therefore, in the present study we have compared the postoperative stability between DO and bilateral sagittal split ramus osteotomy (BSSRO) in mandibular retrognathism. Methods: Seven patients who had been treated by DO and thirteen patients with BSSRO were included in this study. Serial lateral cephalograms were analyzed by manual tracing and the amount of the mandibular elongation was measured. To evaluate the postoperative stability, positional changes of the condylar position and B point were analyzed. Results: Mean amount of mandibular advancement was $6.51{\pm}3.57mm$ for BSSRO group and $12.43{\pm}4.35mm$ for DO group, respectively. There was no significant difference in age between the two groups (P>0.05). Mean follow up periods were 10.77 months for BSSRO group and 11.28 months for DO group, respectively. After mandibular advancement, mean positional changes in the condyle were $0.56{\pm}1.43mm$ horizontally and $0.72{\pm}1.61mm$ vertically for BSSRO group and $0.53{\pm}1.56mm$ horizontally and $0.56{\pm}1.75mm$ vertically for DO group, respectively. Mean change of distance from B point to Y-axis was $-1.76{\pm}0.83mm$ for BSSRO group and $-2.14{\pm}1.82mm$ for DO group, respectively. According to the condylar position and B point, there were no significant differences in postoperative stability between the two groups (P>0.05). Conclusion: There was no significant difference in postoperative stability between DO and BSSRO group according to condylar position and B point. Based on the results of the present study, it is hypothesized that DO would be a good treatment choice for severe mandibular retrognathism because DO could achieve more mandibular advancement and concurrent soft tissue elongation.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.5
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• pp.316-323
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• 2009

Purpose: This study was performed to evaluate three-dimensional positional change of the condyle using 3D CT after bilateral sagittal split ramus osteotomy (BSSRO) in skeletal class III patients. Patients and methods: Nine patients who underwent BSSRO for mandibular set-back in skeletal class III malocclusion without facial asymmetry were examined. Miniplates were used for the fixation after BSSRO. 3-D CT was taken before, immediately after, and 6 months after undergoing BSSRO. After creating 3D-CT images using V-works $4.0^{TM}$ program, axial plane, coronal plane, & sagittal plane were configured. Three dimensional positional change, from each plane to the condyle, of the nine patients was measured before, immediately after, and 6 months after undergoing BSSRO. Results: 1. The mean value of mandibular set-back for nine mandibular prognathism patients was 7.36 mm (${\pm}\;2.42\;mm$). 2. In the axial view, condyle is rotated inward immediately after BSSRO (p < 0.05), comparing with preoperative but outward 6 months after BSSRO comparing with postoperative (p < 0.05). 3. In the axial view, condyle is moved laterally immediately after BSSRO (p < 0.05), comparing with preoperative but regressed 6 months after BSSRO comparing with preoperative (p > 0.05). 4. In the frontal & coronal view, there is changed immediately after and 6 months after BSSRO, comparing with preoperative but no statistical difference. Conclusion: These results indicate that three-dimensional positional change of the condyle in skeletal class III patients is observed lateral displacement & inward rotation immediate after BSSRO, but the condyle in 6 months after BSSRO tends to regress to preoperative position.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.32.1-32.4
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• 2020

Background: Le Fort I osteotomy is a highly effective treatment for skeletal jaw deformities and is commonly performed. High Le Fort I osteotomy is a modified surgical procedure performed for improving the depression of the cheeks by setting the osteotomy higher than the conventional Le Fort I osteotomy. Developments in three-dimensional (3D) technology have popularized the use of 3D printers in various institutions, especially in orthognathic surgeries. In this study, we report a safe and inexpensive method of performing a high Le Fort I osteotomy using a novel 3D device and piezosurgery, which prevent tooth root injury without disturbing the operation field for patients with a short midface and long tooth roots. Results: A 17-year-old woman presented with facial asymmetry, mandibular protrusion, a short midface, and long tooth roots. We planned high Le Fort I osteotomy and bilateral sagittal split ramus osteotomy. Prevention of damage to the roots of the teeth and the infraorbital nerve and accurate determination of the posterior osteotomy line were crucial for clinical success. Le Fort I osteotomy using 3D devices has been reported previously but were particularly large in size for this case. Additionally, setting the fixing screw of the device was difficult, because of the risk of damage to the roots of the teeth. Therefore, a different surgical technique, other than the conventional Le Fort I osteotomy and 3D device, was required. The left and right parts of the 3D device were fabricated separately, to prevent any interference in the surgical field. Further, the 3D device was designed to accurately cover the bone surface from the piriform aperture to the infra-zygomatic crest with two fixation points (the anterior nasal spine and the piriform aperture), which ensured stabilization of the 3D device. The device is thin and does not interfere with the surgical field. Safe and accurate surgical performance is possible using this device and piezosurgery. The roots of the teeth and the infraorbital nerve were unharmed during the surgery. Conclusions: This device is considerably smaller than conventional devices and is a simple, low-cost, and efficient method for performing accurate high Le Fort I osteotomy.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.1
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• pp.25-29
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• 2015

Factor XI deficiency (Hemophilia C) is a very rare autosomal recessive bleeding disorder. Patients with factor XI deficiency do not typically show any spontaneous bleeding or specific symptoms. Sometimes those who have this disorder are identified during special situations such as trauma or surgery. Orthognathic surgery is particularly associated with a high bleeding risk. Therefore, great care must be taken when treating patients with bleeding disorders such as factor XI deficiency. There are a few reports that address the management of patients with bleeding disorders during orthognathic surgery. The current report describes a patient with factor XI deficiency who underwent Le Fort I osteotomy together with bilateral sagittal split osteotomy. The patient's condition was assessed using both rotation thromboelastometry ($ROTEM^{TM}$) and noninvasive measurements of total hemoglobin (SpHb) using Masimo Radical 7 (Masimo Co. CA, USA).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.4
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• pp.348-356
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• 2001

The factors related to relapse in 20 skeletal class III patients who performed two-jaw surgery with Le Fort I maxillary osteotomy and bilateral sagittal split ramus osteotomy was investigated. All patients were fixed with miniplate on the maxilla and three screws at each mandible. Cephalograms taken at preoperative, immediate postoperative and 8 months postoperative after surgery were traced and digitized. 1.The horizontal and vertical relapse of maxilla and mandibular chin points was within 1mm postoperatively. Compare to the preceding report concerning the mandibular set-back surgery only group, this reveals two-jaw surgery for mandibular prognathism using rigid fixation is more stable. 2.Although there was no significant relapse tendancy was observed at chin points, the screw tip land-marks moves anterio-superiorly and each side of the screws moved as a one unit. The screw tip points moved similar direction to the masticatory force and this movements might be influenced by the muscular tension to the distal segment of the mandible. 3.According to the regression analysis, the amount of horizontal and vertical movement of mandibular set-back influenced the mandibular relapse. However, direction and amount of maxillary surgical movement did not inf1uenced the maxillary and mandibular relapse.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.4
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• pp.351-358
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• 2010

A 31-year-old woman with hemifacial microsomia presented to the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. The patient was previously treated with distraction osteogenesis device to elongate right maxilla and mandibular ramus. But, the result was not satisfactory, to correct residual facial asymmetry due to hemifacial microsomia we planned costochondral graft for reconstruction of ramus and condyle, Le Fort I osteotomy and sagittal split ramus osteotomy for facial asymmetry. The right mandibular condyle and ramus was reconstructed with right eleventh costochondral graft via submandibular approach. Using costochondral graft and orthognathic surgery the facial asymmetry in hemifacial microsomia patient was corrected. 1-stage treatment consists of costochondral graft and orthognathic surgery can achieve function and esthetics at the same time, is timesaving to both patient and surgeon.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.22 no.4
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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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• v.28 no.2
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• pp.126-131
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• 2002

Anatomical shape of the mandibular ramus, which includes the area from the rear of the mandibular second molar to the mandibular posterior border and from the mandibular sigmoid notch to the inferior mandibular border, must be carefully considered to perform orthognathic surgery. The locations of the lingula and mandibular foramen in medial side of mandibular ramus are one of the most important factors to decide the location of the horizontal medial osteotomy in sagittal split ramus osteotomy and to select the line of vertical osteotomy in intraoral vertical ramus osteotomy. Sixty-five different Korean human dry mandibles were surveyed. All mandible have permanent dentition including complete eruption of the mandibular second molar. The locations of the lingula and mandibular foramen in medial side of the ramus were identified and following results were obtained. Anterior ramal horizontal distance from lingula was $16.13{\pm}3.53mm(range:8.6{\sim}24.3mm)$, anterior ramal horizontal distance from mandibular foramen was $23.91{\pm}4.79mm(range: 14.1{\sim}39.7mm)$, horizontal width of mandibular foramen was $2.79{\pm}0.95mm(range:1.5{\sim}6.1mm)$, height of lingula was $10.51{\pm}3.84mm(range:3.1{\sim}22.4mm)$, vertical distance from sigmoid notch to lingula was $19.82{\pm}5.11mm(range:9.1{\sim}35.3mm)$. From this study, the result could be used to select the location of osteotomy lines and to decide amount of periosteal elevation to avoid injury of neurovascular bundle, and to accomplish the appropriate split in Korean patients in mandibular orthognathic surgery.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.12 no.2
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• pp.9-20
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• 1990

A series of 19 cases with maxillary hyperplasia and mandibular retrognathia were operated on by simultaneous superior repositioning of the maxilla after Le Fort I osteotomy and anterior repositioning of the mandible after bilateral sagittal split ramus osteotomies with or without osteotomy of the inferior border of the mandible. These were evaluated by retrospective cephalometric and computer analysis for the longitudinal skeletal and dental changes for an average of 17.1 months after surgery. For stabilization of the osteotomized segments, the authors used wire osteosynthesis by means of bilateral infraorbital and zygomatic buttress suspension wire at the maxilla, and direct interosseous wire at the split segments of the mandibular rami. Results show generally good stability after simultaneous maxillary and mandibular surgery with wire osteosynthesis, and a minimal to moderate tendency toward skeletal and dental relapse. This article is a preliminary study to defy the efficiency of the wire osteosynthesis (wo)compared with rigid internal fixation (RIF) for simultaneous maxillary and mandibular surgery. 1. The vertical relapse rate of the A point after superior repositioning of the maxilla is 2.2%. 2. The horizontal relapse rate of the B point after advancement of the mandible is 18.3%. 3. The condyle is distracted inferiorly and slightly posteriorly at the immediate postoperative period. 4. At the long term follow up examination, the condyle presents tendency of return to the preoperative position. 5. Condylar segment angle is decreased at the immediate postoperative period, and at the long term follow up evaluation, the angle is increased. 6. Gonial angle is increased at the immediate postoperative period, and then is decreased at the long term follow up evaluation. 7. The dentition is satisfactory with acceptable movement at the long term follow up evaluation. 8. At the mandibular free body analysis, genioplasty shows good stability. 9. Wire osteosynthesis provides excellent stabilization for the simultaneous maxillary and mandibular surgery.