• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.141-152
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• 1984

The author analysed the bone changes, the positional relationships between condylar head and articular fossa, and the interrelationship between the bone changes and the abnormal position of condylar head, from 1,036 radiographs of 259 patients with temporomandibular joint arthrosis, which were obtained by the oblique-lateral transcranial projection and orthopantomograms. The results were as follows: 1. Among the radiographic bone changes of the temporomandibular joint arthrosis, deformity was 36.90%(217 case), sclerosis 34.18% (20 cases), errosive chang 25.85% (152 cases) and marginal proliferation 3.06% (18 cases) respectively. 2. In the positional changes between condylar head and articular fossa, the downward positioning of condylar head in centric occlusion was most frequent(36.90%), of which frequency was signifiantly higher than forward positioning (11.22%) and backward positioning(4.76%) in same condition. Also, radiographs showed that the enlargement of articular space showed higher frequency than its narrowing. In the opening position of mouth, the restricted movement of condylar head within articular fossa was most frequent(35.03%). The forward positioning and the downward positioning was 15.65% and 9.52% respectively. Also, radiographs revealed that the incomplete movement or no positional change of condylar head was most frequent. 3. In the interrelationship between bone changes and abnormal position of condylar head, deformity was 42.79% in the cases of downward positioning of condylar head in centric occlusion and 37.50% in those of normal positioning of condylar head in same condition. This revealed that deformity was most frequent bone change in above condylar positionings. However, erossive change was 34.62% in the cases of downward positioning of condylar head in centric occlusion and 33.33% in those of forward positioning. In opening position of condylar head, and deformity in the cases of normal positioning, forward positioning and downward positioning of condylar head was 38.38%, 36.96% and 44.64% respectively. 4. Bone changes of condylar head was 47.11%, articular eminence 41.50% and articular fossa 11.39% respectively. This revealed that the frequencies of bone changes. were higher in the projected portion of bony structures of temporomandibular joint than their depressed portions. On the otherhand, in the bone changes of condylar head, deformity was 59.57% which was the most frequent. In the bone changes of articular eminence and articular fossa, however, sclersis was 41.39% and 65.67% respectively, which was the most frequent in those portions.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.11 no.1
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• pp.79-87
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• 1981

The author analysed the interrelation between the morphologic changes of bone Structures and the position of condylar head from the routine radiographs of 134 cases of the temporomandibular joint arthrosis. The frequencies of coincidence between the site of bone defrmity and condylar head positional change were examined. Also, the positional changes of condylar head and the direction of condylar movement in relation to the kind of bone deformities were observed. The results obtained were as follows; 1. In 52.65 per cent of total cases, the site, of positional change of condylar head was coincided with the site of bone deformans. The frequencies of the coincidence between these in the five items among seven items examined were above 53 per cent. From the results, it seems that the positional changes of condylar head were related with the morphological change of bone structure. 2. Eburnation and erosion. revealed frequently positional changes in the opening and closing position of the mouth, although in the early stages of the TMJ arthrosis. 3. In the bone deformans, during opene position of the mough 44.81 per cent of total cases revealed backword movement and 37.74 per cent showed forward movement. In closed position of the mouth, downward movement was revealed in 35.23 per cent of total cases and upward movement 28.41 per ,cent of total cases. 4. In the cases showing eburnation, the frequencies of coincidence between the site of positional change and bone deformans were 58.57 per cent of the total cases. that means it was high in the early stages of the TMJ arthrosis.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.40
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• pp.13.1-13.8
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• 2018

Background: We evaluated change in the mandibular condyle after orthognathic surgery using cone-beam computed tomography (CBCT) in patients with facial asymmetry. Methods: Thirty patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry were classified into two groups according to the amount of menton deviation (MD) from the facial midline on anteroposterior (AP) cephalogram: group A (asymmetry, MD ≥ 4 mm; n = 15) and group B (symmetry, MD < 4 mm; n = 15). Position and angle of condylar heads on the axial, sagittal, and coronal views were measured within 1 month preoperatively (T0) and postoperatively (T1) and 6 months (T2) postoperatively. Results: On axial view, both groups showed inward rotation of condylar heads at T1, but at T2, the change was gradually removed and the condylar head returned to its original position. At T1, both groups showed no AP condylar head changes on sagittal view, although downward movement of the condylar heads occurred. Then, at T2, the condylar heads tended to return to their original position. The change in distance between the two condylar heads showed that they had moved outward in both groups, causing an increase in the width between the two heads postoperatively. Analysis of all three-dimensional changes of the condylar head positions demonstrated statistically significant changes in the three different CBCT views in group B and no statistically significant changes in group A. Conclusions: There was no significant difference between the two groups in condylar head position. Because sagittal split ramus osteotomy can be performed without significant change in symmetrical and asymmetrical cases, it can be regarded as an effective method to stabilize the condylar head position in patients with skeletal class III malocclusion and mandibular prognathism or facial asymmetry.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.13 no.1
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• pp.7-15
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• 1983

The purpose of this study was to investigate the radiographic images of the condylar head in clinically normal subjects and the TMJ patients using standardized projection technique. 45 subjects who have not clinical evidence of TMJ problems and 96 patients who have the clinical evidence of TMJ problems were evaluated, but the patients who had fracture, trauma and tumor on TMJ area were discluded in this study. For the evaluation of radiographic images, the author has observed the condylar head positions in closed mouth and 2.54㎝ open mouth position taken by the standardized transcranial oblique lateral projection technique. The results were as follows: 1. In closed mouth position, the crest of condylar head took relatively posterior position to the deepest point of the glenoid fossa in 8.9 % of the normals and in 26.6% of TMJ patients. 2. In 2.54㎝ open mouth position, condylar head took relatively posterior position to the articular eminence in 2.2% of TMJ patients and 39.6% of the normals. 3. In open mouth position, the horizontal distance from the deepest point of the glenoid fossa to the condyla head was 13.96㎜ in the normals and 10.68㎜ in TMJ patients. 4. The distance of true movement of condyalr head was 13.49㎜ in the normals and l0.27㎜ in TMJ patients. 5. The deviation of mandible in TMJ patients was slightly greater than that of the normals.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.57-65
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• 1983

The purpose of this study was to investigate the range of condylar movement of children with young permanent dentition. Materials included 33 roentgenograms of 4 serial projections of TMJ by modified transcranial projection with Accurad 100. Four serial projections were taken in the centric occlusion, rest position, 1 inch open, and maximum open position. The results obtained from this study were as follows. 1. The condyle was located anteriorly in articular fossa at centric occlusion. 2. The condyle was moved forwardly and downwardly during mandibular movement from centric occlusion to maximum open position. 3. The pattern of condylar movement was similar in both sexes, but there were no sex differences in distance of condylar movement.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.5
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• pp.359-367
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• 2004

Purpose: After the surgical correction with sagittal split ramus osteotomy, the position of the mandibular condyle in the glenoid fossa and the proximal segment of the mandible change because of bony gap between proximal and distal segment, especially in case of mandibular setback asymmetrically. In this study, positional changes in the condyle and proximal segment after BSSRO were estimated in the mandibular asymmetry patient by analyzing the in submentovertex view and P-A cephalogram for identification of ideal condylar position during surgery. Patients and Methods: The 20 patients were selected randomly who visit Dankook Dental Hospital for mandibular asymmetry. Bilateral sagittal split ramus osteotomy with rigid fixation was performed and P-A cephalogram and submentovertex view was taken at the time of preoperative, immediate postoperative, 3 month postoperative period. Results: Intercondylar length and transverse condylar angle was increased due to inward rotation of proximal segment and anteromedial rotation of lateral pole of condyle head. The condylar position had a tendency to return to the preoperative state and after 3 months return up to about half of the immediate post-operative changes, and all the results showed more changes in asymmetry patient and deviated part of the mandible. Conclusion: Based on all these results above, surgeon should make efforts to have a precise preoperative analysis and to have a ideal condylar position during rigid fixation after BSSRO.

• The korean journal of orthodontics
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• v.22 no.4 s.39
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• pp.837-853
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• 1992

The purpose of this study was to investigate the positional changes of the mandibular condyles after orthognathic surgery In patients with severe skeletal Class III malocclusion. This study was based on 21 patients who had received bilateral sagittal split osteotomy for mandibular setback. Among them 14 were fixated non - rigidly (W group), and 7 were fixated rigidly (R group). After submental vertex view analysis, each subject was given the T.M.J. Tomogram in both centric occlusion and centric relation immediate before, $4\~6$ weeks after and more than 6 months after surgery. The anteroposterior and vertical changes between each time interval were measured and analyzed statistically. Following results were obtained. 1. There was no significant difference between right and left condyles in their anteroposterior and vertical changes of the condylar position. 2. In anteroposterior changes of condylar position of the wire fixation group, the condyles were moved anteriorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery. In the rigid fixation group, there was no significant difference in any observation periods of centric occlusion and centric relation. 3. In vertical changes of condylar position of the wire fixation group. the condyles were moved inferiorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery. In the rigid fixation group, the condyles were moved inferiorly 4-6 weeks after surgery, and then the pattern of reestablishment to their preoperative position was observed more than 6 months after surgery in centric occlusion only.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.2
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• pp.130-134
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• 1997

The sagittal split ramus osteotomy(SSRO) of the mandible has used one of the most popula methods for the correction of various dentofacial deformities, especially mandibular prognathism. In SSRO, there are produced bony gap following mandible setback because of mandibular flaring. For this reason, the condylar axis may be changed due to bony approximation both segment in three dimension more mesio-laterally. According to change of condylar position, the condition of TMJ structure are changed and change of TMJ symptoms are suggested theoretically, and the correction of malocclusion by SSRO may improve the TMJ symptoms by improvement of feeding difficulties. The pupose of this study was to determine relationship between expected alterations in condylar position and suggested TMJ symptoms produced by change of condylar position. TMJ symptoms of 15patients who had operated SSRO are checked at about postoperative 6 month ranging $5{\sim}11$ month. Anterior-posterior position of condyle which was comparison preoperative with postoperative position, was classified 5 groups. The author tried to identify relationship between positional change of condyle and TMJ discomfort.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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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.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.121-134
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• 1984

The authors analyzed the morphological change of bone structure from 3,140 radiographs (1570 joints) of 785 patients with temporomandibular joint arthrosis, which were obtained by the oblique lateral transcranial projection and orthopantomographs. The interrelation of bone change and clinical symptoms, duration of the diseases were examined. Also, the bone changes of articular eminence, condyle, articular fossa were examined according to positional change of the condyle in the mouth open and close state. The results were as follows. 1. In the 785 patients with TMJ arthrosis, 782 patients (99.62%) show the positional change of the condyle. Among them 691 patients (88.03%) show the bone change. 2. In TMJ arthrosis patients with bone changes 451 patients (65.27%) showed both the condylar positional changes and bone changes bilaterally. 198 patients (28.65%) show the condylar positional changes bilaterally and bone changes unilaterally. 3. The bone changes in the TMJ arthrosis were in order of frequency eburnation (647 cases, 32.8%), erosion (548 cases, 27.79%), flattening (418 cases, 21.20%), deformity (138 cases, 6.99%). sclerosis (115 cases, 5.83%), marginal proliferation (106 cases, 5.38%). The region of bone change in TMJ arthrosis with condylar positional changes were in order of frequency the articular eminence (43.97%) condylar head (38.64%), articular fossa (17.39%). In the patients with bone changes, their clinical symptoms were pain (44.34%), clicking sound (33.5%), limitation of mouth opening (22.52%). In the patients complaining pain the most frequent bone change was erosion (28.60%), in the patients complaining clicking sound, eburnation (28.97%) in the patients complaining the limitation, eburnation (29.40%). Also in the patients with the duration below 1 year most common bone change was eburnation. 5. The most common condylar positional change was downward position (39.94%) in closed state, restricted movement of condyle (30.07%) in open state. The condylar positional changes and bone changes according to the region were as follows: a) In the condylar head the most frequent bone change was erosion (30.45%) and the most frequent condylar positional change was downward position (37.40%) in closed state, restricted movement of condyle (33.2%) in open state. b) In the articular eminence the most frequent bone change was eburnation (39.91%) and the most frequent condylar positional change was downward position (39.79%) in closed state, restricted movement of condyle (27.22%) in open state. c) In the articular fossa the most frequent bone change was eburnation (53.94%) and the most frequent condylar positional change was downward position (42.57%) in closed state, restricted movement of condyle (30.32%) in open state.