• The korean journal of orthodontics
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• v.54 no.4
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• pp.247-256
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• 2024

Objective: This retrospective study evaluated the mandibular condyle position before and after bimaxillary orthognathic surgery performed with the mandibular condyle positioned manually in patients with mandibular prognathism using cone-beam computed tomography. Methods: Overall, 88 mandibular condyles from 44 adult patients (20 female and 24 male) diagnosed with mandibular prognathism due to skeletal Class III malocclusion who underwent bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I performed using the manual condyle positioning method were included. Cone-beam computed tomography images obtained 1-2 weeks before (T0) and approximately 6 months after (T1) surgery were analyzed in three planes using 3D Slicer software. Statistical significance was set at P < 0.05 level. Results: Significant inward rotation of the left mandibular condyle and significant outward rotation of the right mandibular condyle were observed in the axial and coronal planes (P < 0.05). The positions of the right and left condyles in the sagittal plane and the distance between the most medial points of the condyles in the coronal plane did not differ significantly (P > 0.05). Conclusions: While the change in the sagittal plane can be maintained as before surgery with manual positioning during the BSSRO procedure, significant inward and outward rotation was observed in the axial and coronal planes, respectively, even in the absence of concomitant temporomandibular joint disorder before or after the operation. Further long-term studies are needed to correlate these findings with possible clinical consequences.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.21.1-21.6
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• 2020

Background: Fibula free flap mandible reconstruction is the standard procedure after wide resection of the mandible. Establishment and maintenance of normal occlusion are important in mandible reconstruction both intraoperatively and after surgery. However, scar formation on the surgical site can cause severe fibrosis and atrophy of soft tissue in the head and neck region. Case presentation: Here, we report a case of severe soft tissue atrophy that appeared along with scar formation after mandibular reconstruction through the fibular free flap procedure. This led to normal occlusion collapse after it was established, and the midline of the mandible became severely deviated to the affected side that was replaced with the fibula free flap, leading to facial asymmetry. We corrected the malocclusion with a secondary operation: a sagittal split ramus osteotomy on the unaffected side and a sliding osteotomy on the previous fibula graft. After a healing time of 3 months, implants were placed on the fibula graft for additional occlusal stability. Conclusion: We report satisfactory results from the correction of malocclusion after fibula reconstruction using sliding fibula osteotomy and sagittal split ramus osteotomy. The midline of the mandible returned to its original position and the degree of facial asymmetry was reduced. The implants reduced difficulties that the patient experienced with masticatory function.

• Imaging Science in Dentistry
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• v.32 no.3
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• pp.167-173
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• 2002

Purpose : To evaluate clinical and radiographic differential diagnosis between ameloblastoma and odontogenic keratocyst (OKC) using clinical data, plain radiographs, and CT. Materials and Methods: 25 cases of ameloblastoma and 44 cases of OKC diagnosed in biopsy, were selected from the files stored in Department of Oral and Maxillofacial Radiology, Seoul National University Dental Hospital from 1999 to 2001, and evaluated using following criteria: sex and age, location, shape, border to normal bone tissue, effect to adjacent tissues, homogeneity in the lumen of the lesion, response of the cortical bone, long-to-short length (LIS) ratio of the lesion, and expansion angle of the cortex. Results: Ameloblastoma and OKC were seen most frequently in third decades and no statistical significance was noted between both sexes. Ameloblastoma occurred most frequently in mandibular angle and ramus area (68%) and OKC at the maxillary molar (34.1 %), and mandibular angle and ramus area (43.2%). The root resorption of the adjacent teeth, mandibular canal displacement, and the impaction of teeth were seen more frequently in ameloblastoma than in OKC. The LIS ratio measured in CT was largest in maxillary OKC cases, followed by mandibular ameloblastoma, and mandibular OKC (1.2, 1.8 and 2.4 respectively). The expansion angle of the cortex shows a statistically significant difference between ameloblastoma (48.8°) and OKC (31.5°). Conclusion : The numeric morphology (LIS ratio) and expansion angle of the cortical bone of the lesion measured in computed tomography can be used to differentiate the ameloblastoma and odontogenic keratocyst.

• Journal of Yeungnam Medical Science
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• v.6 no.2
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• pp.183-194
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• 1989

This is a report of 2-cases of mandibular prognathism corrected by Intraoral oblique splitting osteotomy of mandibular ramus. The Intraoral oblique splitting osteotomy is a modification of sagittal split osteotomy of ramus and it is documented by Yoshida, on 1985. By this method. authors obtained the following results. 1. The patients' esthetic, psychological and functional problems were dissolved by setback of mandibular prognathism. 2. The postoperative infection, splitted bone segments fracture, paresthesia of the face and T.M.J. dysfunction were not appeared. 3. Postoperative intermaxillary fixation was maintained for 8 weeks. The patients could open their mouths in normal range after a week of intermaxillary fixation removal. 4. The soft tissue changes of lower lip and chin were about 1:1 to the hard tissue changes. 5. During intermaxillary fixation period and postoperative orthodontic treatment, slight relapse was observed. Now, the patients are under postoperative orthodontic treatment.

• 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.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.3
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• pp.270-276
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• 2001

The treatment of mandibular subcondylar fractures is a matter of controversy. The majority of mandibular subcondylar fracture are treated by closed reduction, but the displaced or dislocated mandibular subcondylar fractures may be treated by open reduction. The characteristics of open reduction are the anatomical reduction, the functional restoration, the rapid function, the maintenance of vertical ramus dimension, the better appearance and the less resultant TMJ problem etc. When an open reduction is considered, the wire, miniplate, lag screw and Kirschner wire are available with internal fixation. Of these, Kirschner wire is a simple method relatively and correct positioning of the wire achieves rigid fixation. But many open reduction methods for mandibular subcondylar fractures require extraoral approach. The extraoral approach has some problems, the facial scar and the risk of facial nerve injury. On the other hand, the intraoral approach eliminates the potency of the facial scar and the facial nerve injury, but is difficult to access the operation site. Since the intraoral approach was first described by Silverman (1925), the intraoral approach to the mandibular condyle has been developed with modifications. The purpose of this article is to describe the intraoral technique with the Kirschner wire on mandibular subcondylar fractures. Conclusion : The intraoral reduction with Kirschner wire on mandubular subcondylar fractures avoids the facial scar and facial nerve injury and is simple method to the extraoral approach. And it has minimal morbidity and better esthetics.

• The Journal of the Korean dental association
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• v.45 no.8 s.459
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• pp.483-490
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• 2007

The aim of this study was to investigate the relationship between the mandibular antegonial notch and the mandibular morphology, and the curve of Spee in anteroposterior skeletal relationship. Pre-treatment lateral cephalograms were obtained from 80(male 34, female 46) adult orthodontic patients and the samples were classified into 3 categories by ANB angle($0^{\circ}$$\leq$ANB< $4^{\circ}$ Class I, $4^{\circ}$$\leq$ANB Class II, ANB< $0^{\circ}$ Class III). The curve of Spee was measured directly from the pre-treatment mandibular study cast of each patient included in this study. Pearson correlation coefficient test and multiple regression analysis in each group revealed the following results; 1. Antegonial notch depth was positively correlated with hoth lower anterior facial height(ANS-Me) in skeletal Class I, II and III groups and Id-Me height in skeletal Class I and II groups. 2. A statistically significant negative correlation was found between the depth of the antegonial notch and the curve of Spee in the Class III group. 3. Significant relationship was not found between the antegonial notch depth and any of the other cephalometric variables such as mandibular body length(Go-Gn) and ramus height(Co-Go). As antegonial notch depth increased, more vertical growth of the mandible was observed. Antegonial notch can be used as a predictor of vertical mandibular growth in the diagnosis and treatment planning of malocclusion.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.4
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• pp.253-256
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• 2009

Schwannoma(neurilemmoma) is a benign neoplasm that originates from the Schwann cells. Schwannoma most commonly arises in the soft tissue of the head and neck. Intraoral lesions are uncommon, however, and intraosseous schwannoma are even rare. The most common site of occurrence for these unusual lesions is the mandible. This article documents a case of an intraosseous schwannoma located in the mandibular ascending ramus. The lesion was surgically removed and no radiographic evidence of recurrence was observed after 1 year.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.16 no.1
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• pp.19-24
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• 1986

The author performed radiographical analysis of the third molar dentition and characteristic relation to anatomical oral structure. For this purpose 506 orthopantomagraph film, male 283cases and female 223 cases, aged from 15 to 30 years were evaluated by means of Winter's classification in conjunction with some other methods. Through the study following results were obtained; 1. The eruption of(equation omitted) were found in 229 cases followed by 61 cases of(equation omitted) and 45 cases showed no evidence of eruption. 2. The classification based on the relation of ramus to distal portion of the 2nd molar revealed class Ⅱ, 460 cases (61.8%) and 182 cases (24.5%) were class Ⅲ. 3. Parallelism between long axis of mandibular third molar and the second molar were found in 302 cases (40.8%) and mesial inclination of the third molar were 280 cases (37.6%). 4. Average inclination degree among these cases showed 138.62±12.56°.

• Imaging Science in Dentistry
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• v.33 no.4
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• pp.231-234
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• 2003

We report a case of pilomatrixoma presenting in the right cheek of a 6-year-old girl. In the panoramic view, a small, ovoid-shaped, and nonhomogenous calcified mass was superimposed on the right mandibular angle, The mass was located on the skin overlying the right mandibular ramus area in the skull P-A view. The tumor had a strongly reflective pattern with acoustic shadowing in sonographic view. We also illustrate how these lesions can be effectively diagnosed.