• 대한치과보철학회지
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• 제26권1호
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• pp.63-84
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• 1988

Recently the instantaneous centre concept has been used to understand the biomechanics by which a tissue derangement causes a mechanical derangement in temporomandibular joint. In this study, four male subjects without temporomandibular joint disorder and malocclusion were selected for the determination of the instantaneous centre of rotation (I.C.R) in the mandibular movement. The habitual opening and closing paths were recorded on the sagittal plate by two spring pencils attached on the lower anterior teeth which was designed for this study, and the I.C.R. was calculated by the computer program of Rouleaux's method. Also the computer graphic opening and closing movements of mandible were obtained according to the determined I.C.R. The results obtained from this study were as follows. 1. The instantaneous centres of rotation were not positioned within the condyle in the mandibular opening and closing movement. 2. There was some similarity between the anatomical curvature of the articular emience and the movement pattern of condyle. 3. The opening path and the closing path of the most superior pl)int of the condyle stowed a slight difference. 4. At the early stage of the habitual opening movement, the condyle was moved downward. 5. The opening and closing mandibular movements were simulated by the instantaneous centre of rotation which was determined by the computer program of Rouleaux's method.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제35권3호
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• pp.189-194
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• 2013

Osteochondroma is a benign neoplasm, osseous projection surrounded with cartilage, 35.8% of benign osseous tumor, 8.5% of whole osseous tumor and usually arises from the skeletal bone. Osteochondroma is a cartilaginous derivation and relatively uncommon in the craniofacial bone. Osteochondroma of the mandible has slow growth rates which mainly affect women around forty years of age and it can appear through the coronoid process and mandibular condyle, especially in the medial half. Clinical finding associated with osteochondroma of condyle are primarily a palpable, painless temporomandibular area mass with facial asymmetry, malocclusion and midline deviations. Sometimes pain and dysfunction like trismus often accompany the anatomic derangement. Other features include malocclusion with open-bite on the affected side and cross-bite on the contralateral side. In this study, a 45-years old female patient exhibits pain on the left temporo-mandibular joint area and malocclusion due to loss of the molar region with osteochondroma on the top left of her mandibular condyle head. The patient is able to recover gradually from the symptom through treatments on manipulation, stabilization splint, arthroscopic lavage and surgical excision, thus, this is reported as a clinical case.

• Imaging Science in Dentistry
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• 제38권1호
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• pp.23-27
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• 2008

Purpose: The aim of this study was to evaluate the change in the position of the mandibular condyle within articular fossa by a CBCT after wearing complete denture (CD). Materials and Methods: CBCT of 34 temporomandibular joints were taken from 9 male and 8 female patients with CB $Mercuray^{TM}$ (Hitachi, Japan) before and after wearing a CD for rehabilitation. Position of mandibular condyle within articular fossa at centric occlusion was evaluated with $Vimplant2.0^{TM}$ (CyberMed, Korea) on the central parasagittal view and curved panoramic coronal view of the condylar head. A statistical evaluation was done with SPSS. Results: The range of anteroposterior positional rate (AP) of condylar head within articular fossa was -16-5 and -10-12 respectively on the right and left sides. Before wearing CD, the AP rate showed discrepancy between right and left sides (p<0.05). After wearing CD, both condyles showed a tendency to decrease in posterior condylar position (right side; p<0.05). The average discrepancy between right and left side in mediolateral positional rate (MD) was 15.5 and 4.5 respectively before and after wearing CD. The improvement was observed in mediolateral relationship of both condylar heads after wearing CD (p< 0.01). Before wearing CD, the average horizontal angle of long axis of condylar head was $79.6{\pm}2.7^{\circ}\;and\;80.1{\pm}5.7^{\circ}$ respectively on the right and left sides. After wearing CD, both condyles were rotated in the same direction in average on axial plane. Conclusion: We observed with CBCT the significant clinical evidence in case of positional change of mandibular condyle after wearing complete denture.

• Journal of Oral Medicine and Pain
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• 제48권4호
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• pp.152-158
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• 2023

Purpose: This pilot study aimed to evaluate changes in joint space (JS) using cone-beam computed tomography (CBCT) images of patients diagnosed with temporomandibular joint (TMJ) osteoarthritis (OA) and to determine the association between occlusal changes and JS. Methods: CBCT images were used to measure the anterior, superior, and posterior JSs of the sagittal plane. The differences in JS values over time and between groups were compared. The percentage change in the anteroposterior position of the mandibular condyle between groups was also analyzed. Results: Thirty-four subjects (mean age=43.91±20.13), comprising eight males (23.5%) and 26 females (76.5%), were divided into 18 patients with no change in occlusion (NCO) and 16 patients with a change in occlusion (CO) during TMJ OA. The JS measurements of the study subjects showed a decrease in anterior joint space (AJS) values over time. There was no difference in JS measurements between the groups at T1 and T2. AJS values measured at T1 were lower in the CO group than in the NCO group, but the difference was not statistically significant. In both groups, a posterior position of the mandibular condyle was initially observed with high frequency. However, there is a statistically significant difference in CBCT images taken after occlusal changes, with an increased frequency of condyles observed in the anterior or central positions. Conclusions: In conclusion, AJS decreased over time in TMJ OA, and the mandibular condyle became more anteriorly positioned with occlusal changes. Therefore, clinicians should diligently monitor mandibular condyle morphology and JS using CBCT, along with the patient's clinical symptoms, to treat and control TMJ OA effectively.

• 치과방사선
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• 제23권2호
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• pp.207-211
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• 1993

The auther has evaluated the panoramic image of the mandibular condyle according to its horizontal codylar angle(0°, 10°, 20°, 30°, 40°) and intercondylar distance( 9.5, 11.0, 12.5, 14.0㎝). The Results were as follows: 1. In all horizontal condylar angle, the farther the intercondylar distance was, the smaller the horizontal length in radiogram was. 2. The increased the horizontal condylar angle was, the longer in horizontal direction and the shorter in vertical direction the image of superior condylar surface was. 3. In case of large horizontal condylar angle, the real mesial surface of condyle was projected to the posterior surface on radiograph.

• Imaging Science in Dentistry
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• 제39권2호
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• pp.93-98
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• 2009

Purpose: To classify and evaluate the mandibular fractures. Materials and Methods : The author classified the mandibular fractures of 284 patients who were referred to the Chonbuk National University Dental Hospital during the period from March 2004 to June 2007. This study was based on the conventional radiographs as well as computed tomographs which were pertained to the 284 patients who have had the mandibular fractures including the facial bone fractures. And mandibular fractures were classified with respect to gender, age, site and type of the fractures. Results: More frequently affected gender with mandibular fracture was male with the ratio of 3.3:1. The most frequently affected age with mandibular fracture was third decade (38%), followed by fourth decade (16%), second decade (15%), fifth decade (11 %), sixth decade (7%), seventh decade (5%), eighth decade (4%), first decade (4%), and ninth decade (0.3%). The most frequent type of mandibular fracture was single fracture (58%), followed by double fracture (39%), triple fracture (3%). The most common site of mandibular fracture was mandibular condyle as 113 cases (27.7%) and the next was mandibular symphysis as 109 cases (26.7%), mandibular angle as 103 cases (25.3%), mandibular body as 83 cases (20.3%) in order. The sum of fracture sites were 408 sites and there were 1.4 fracture sites per one patient. The number of mandible fractures accompanied with facial bone fractures were 41 cases (14.4%). Conclusion: The results showed the most frequent type and common site of mandibular fracture was single fracture and mandibular condyle respectively. (Korean J Oral Maxillofac Radiol 2009; 39: 93-8)

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권5호
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• pp.472-477
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• 2005

저자 등은 1996년 1월부터 2004년 12월까지 서울대학교 보라매병원 구강악안면외과에서 치료받은 141명의 하악골 골절 환자의 임상적 연구를 통하여 다음을 알 수 있었다. 1. 전체 환자에서 남,녀 성별 발생빈도는 5.13대 1로 남자에서 호발 하였으며, 연령대별로는 20대에서 가장 빈발하였고 (30.5%), 그 다음 30대, 40대 (22.7%) 순이었다. 2. 하악골 골절의 원인으로 폭행 (45.4%), 낙상, 추락 및 충돌 (40.4%), 교통사고 (11.3%) 순이었다. 3. 골절부의 위치는 하악 정중부 (41.2%), 우각부(32.2%), 과두부 골절(18.5%)의 순으로 나타났으며, 단일 골절의 경우 하악 우각부 골절이 (46.7%)로 가장 많았고, 두 군데 이상의 골절의 하악 정중부 및 우각부 동시 골절이 가장 많았다 (45.5%). 4. 교통사고로 인한 하악 골절은 정중부, 과두부, 우각부 골절의 순으로 발생 빈도를 보였고, 폭력과 낙상, 추락 및 충돌 등으로 인한 골절의 경우 정중부, 우각부, 과두부 골절 순으로 발생빈도를 보였다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제38권
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• pp.24.1-24.7
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• 2016

Background: This study aimed to evaluate the structural changes of temporomandibular joint immediately after condylar fractures with magnetic resonance imaging (MRI). Method: We evaluated 34 subjects of condylar fractures with MRI. The position, shape, and signal intensity of the condyle, disc, and retrodiscal tissue were analyzed with MR images. Results: Immediately after trauma, the disc was displaced with the fractured segment in almost all cases. And, the changes of signal intensity at the retrodiscal tissue were found but less related to the degree of fracture displacement. And, the high signals were observed almost at all fractured joint spaces and even at some contralateral joints. Conclusions: The displaced disc as well as the increased signal intensity of the joint space, condylar head, and retrodiscal tissue demands more attention to prevent the possible sequela of joint.

• 구강회복응용과학지
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• 제22권4호
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• pp.283-288
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• 2006

There are several manners for surgical approaches to the mandibular condyle. With the retromandiular approach, the condyle and fracture are exposed directly and allow for good inspection and reduction. The retromandibular scar is very well camouflaged and practically invisible. The aim of this study was to evaluate clinical results of retromandibular approach for the reduction and fixation of fractured mandibular condyles. We described postoperative complications such as temporary facial nerve weakness involving the marginal mandibular branch, mouth opening limitation and malocclusion in 13 patients with mandubular condylar fractures; 11 subcondylar fractures and 2 condylar neck fractures. The follow-up period was longer than 6 months in all patients. The retromandibular approach was successful in all subcondylar fracture cases. 2 patients with condylar neck fracture had mouth opening limitation and temporary marginal nerve palsy longer than 3 months. But there were no cases of permanent nerve injury and malocclusion. Our findings indicate that retromandibular approach is an easy and safe technique for subcondylar fracture but not for condylar neck fracture.

• Imaging Science in Dentistry
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• 제39권4호
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• pp.205-208
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• 2009

Aneurysmal bone cyst (ABC) is relatively rare, non-neoplastic expansile lesion of bone. The case of a IS-year-old male with a ABC of the left mandibular condyle is presented. Panoramic radiograph showed a unilocular radiolucency with thinned coritces and a subcondylar fracuture which was due to the trauma. Computed tomography (CT) revealed expansile lesion which had similar attenuation soft tissue. The patient was treated surgically including iliac crestal bone graft.