• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.4
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• pp.570-593
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• 1996

This study was intended to perform the influence of condyle positional change after surgical correction of skeletal Class III malocclusion after BSSRO in 20 patients(males 9, females 11) using computed tomogram that were taken in centric occlusion before, immediate, and long term after surgery and lateral cephalogram that were taken in centric occlusion before, 7 days within the period intermaxillary fixation, 24hour after removing intermaxillary fixation and long term after surgery. 1. Mean intercondylar distance was $84.45{\pm}4.01mm$ and horizontal long axis of condylar angle was $11.89{\pm}5.19^{\circ}$on right, $11.65{\pm}2.09^{\circ}$on left side and condylar lateral poles were located about 12mm and medial poles about 7mm from reference line(AA') on the axial tomograph. Mean intercondylar distance was $84.43{\pm}3.96mm$ and vertical axis angle of condylar angle was $78.72{\pm}3.43^{\circ}$on right, $78.09{\pm}6.12^{\circ}$on left. 2. No statistical significance was found on the condylar change(T2C-T1C) but it had definitive increasing tendency. There was significant decreasing of the distance between both condylar pole and the AA'(p<0.05) during the long term(TLC-T2C). 3. On the lateral cephalogram, no statistical significance was found between immediate after surgery and 24 hours after the removing of intermaxillary fixation but only the lower incisor tip moved forward about 0.33mm(p<0.05). Considering individual relapse rate, mean relapse rate was 1.2% on L1, 5.0% on B, 2.0% on Pog, 9.1% on Gn, 10.3% on Me(p<0.05). 4. There was statistical significance on the influence of the mandibular set-back to the total mandibular relapse(p<0.05). 5. There was no statistical significance on the influence of the mandibular set-back(T2-T1) to the condylar change(T2C-T1C), the condylar change(T2C-T1C, TLC-T2C) to the mandibular total relapse, the pre-operative condylar position to the condylar change(T2C-T1C, TLC-T2C), the pre-operative mandibular posture to the condylar change(T2C-T1C, TLC-T2C)(p>0.05). 6. The result of multiple regression analysis on the influence of the pre-operative condylar position to the total mandibular relapse revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condyalr head long axis angle, the more increasing of mandibular horizontal relapse(L1,B,Pog,Gn,Me) on the right side condyle. The same result was founded in the case of horizontal relapse(L1,Me) on the left side condyle.(p<0.05). 7. The result of multiple regression analysis on the influence of the pre-operative condylar position to the pre-operative mandibular posture revealed that the more increasing of intercondylar distance and condylar vertical axis angle and decreasing of condylar head long axis angle, the more increasing of mandibular vertical length on the right side condyle. and increasing of vertical lengh & prognathism on the left side condyle(p<0.05). 8. The result of simple regression analysis on the influence of the pre-operative mandibular posture to the mandibular total relapse revealed that the more increasing of prognathism, the more increasing of mandibular total relapse in B and the more increasing of over-jet the more increasing of mandibular total relapse(p<0.05). Consequently, surgical mandibular repositioning was not significantly influenced to the change of condylar position with condylar reposition method.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.22 no.1
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• pp.77-84
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• 1992

The purpose of this study was to evaluate the diagnostic value of panoramic radiography for diagnosis of temporomandibular joint. Five dry skulls were selected for this study and artificial osteophyte was attached to four different areas of the mandibular condylar head. And then, the author had taken panoramic radiographs with the head in conventional position, 25㎜ forward position and reverse position in mouth opening state. Three dental radiologists evaluated the radiographic images of osteophyte in 60 panoramic radiographs. The results were as follows: In conventional position, osteophyte on the anterolateral and anterocentral area of the condylar head was best seen (p<0.01). In 25㎜ forward position, osteophyte on the anterocentral and anteromedial area was best seen (p<0.05). In reverse position, osteophyte on the anterocentral area was best seen (p<0.05). Osteophyte on anteromedial area was better seen in 25㎜ forward position than in conventional position (p<0.05).

• The korean journal of orthodontics
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• v.36 no.2 s.115
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• pp.136-144
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• 2006

The purpose of this study was to determine whether association exists between temporomandibular joint (TMJ) characteristics in transcranial radiographs and TMJ internal derangement and to evaluate the validity of transcranial radiographs in diagnosis of internal derangement. Transcranial radiographs and magnetic resonance imaging (MRI) of 113 TMJs from 76 subjects were used for this study and all TMJs were classified into 3 groups according to the results of MRI: normal disk position, disk displacement with reduction, and disk displacement without reduction. Transcranial analysis included linear measurement of joint spaces and condylar head angle measurement. To determine any relationship between transcranial measurements according to disk displacement, one-way ANOVA was used. The results showed that condyle-fossa relationship in standard transcranial radiographs had no relationships with disk displacement. And, as disk displacement progressed, condylar angle between head and neck increased significantly. This result can be interpreted that condylar head angle reflects structural hard tissue change according to internal derangement progress. But this is insufficient in the determination of internal derangement. Therefore, although still clinically helpful, the validity of standard transcranial radiographs to diagnose TMJ internal derangement was questioned.

• The korean journal of orthodontics
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• v.20 no.2
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• pp.363-379
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• 1990

The purpose of this study was to evaluate the effects of the mandibular retractive force on the mandibular condyle of growing dog. The experimental animals were six mongrel dogs of two-month old. Their deciduous dentition were completed. Two of them was used as control group, and experimental group was composed of remaining four. Head band and chin cup were made of cotton tape, and hooks are fabricated on the chin cup and had band for closed coil. Mandibular retractive force was 100g/side and chin cap appliance was used for 14 hours/day during night. Experimental group were sacrificed at 2, 4, 6, 8 weeks from beginning of the experiment. Right TMJ was prepared for histologic study and left TMJ was examined grossly for disc, fossa, and condyle. The conclusions are: 1. Two-month old control animal showed active cartilaginous growth on the mandibular condyle, therefore showed thick proliferative and hypertrophic zones. Remodeling process in the condyle head was observed in which there were bone resorption on the anterior surface and bone apposition on the posterior surface. 2. Four-month old control animal showed marked reduction of hypertrophic zone but the condylar bone remodeling was more pronounced. 3. In experimental group, there are marked reduction of hypertrophic zone at 4 weeks from beginning of experiment, and hypertrophic zone disappeared at posterior-superior portion of condyle in 6-week experimental animal. 8 week experimental animal showed slight recovery of hypertrophic zone. 4. In experimental group, bone deposition was increased at anterior surface of condyle, and bone resorption was increased at posterior surface of condyle. 5. In control group, the glenoid fossa and surrounding bone showed mainly bone apposition. But experimental group showed bone resorption at anterior surface of articular eminence and increased bone apposition at posterior surface of postglenoid spine. 6. No marked traumatic change was seen but 4 weeks and 8 weeks experimental animal showed flattening of posterior surperior condylar surface. Bone marrow of condyle showed minute focal bleeding in 2 weeks and 4 weeks experimental animal, and congestion and depression of hematopoietic bone marrow during all experimental period.

• Journal of Oral Medicine and Pain
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• v.22 no.1
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• pp.95-109
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• 1997

The purpose of this research is to investigate the influence on mandibular movements and TMJ sounds with changes of head and neck posture. For the research, twenty patients who had complained of TMJ sounds without any other symptoms of cranio-mandibular disorders, were selected as subjects for measurements of TMJ sounds, and radiographs on transcranial view of TMJ were taken on ten of the subjects. From NHP, UHP, DHP and FHP, aspects of mandibular movement and TMJ sound were investigated from each posture. Aspects of mandibular movement and TMJ sound were observed by measuring total vibration energy(Integral), peak amplitude, maximum amound of mouth opening, and TMJ sound-emitting point using Sonopak for windows (version 1.33) and Bio-EGN(Bioresearch Inc. WI. U.S.A.). Head and neck movement-measuring instrument, CROM(perfomance attainment Inc. U.S.A.) was to maintain even head posture. Degrees of inclination of UHP and DHP were determined at 30' and distance of FHP was 4cm. The results obtained were as follows. 1. Total vibration energy and peak amplitude of TMJ sounds were decreased more on UHP and on UHP and increased more on DHP and FHP than that on NHP. 2. At the maximum mouth opening, distance of TMJ sound-emitting point were decreased more on UHP and increased more on DHP and FHP than that on NHP. 3. The amounts of the maximum mouth opening were increased more on UHP and decreased more on DHP and FHP than that on NHP. 4. For the changes of the head posture with mouth opening observed in radiograph, condylar head was positioned more lower-anteriorly on UHP, and more upper-posteriorly on DHP and FHP than that on NHP. From the results obtained as above, considering positive influence of the change of head and neck posture, avoiding down-head and forward-head posture, and recommending upper- head posture can prevent the progress of temporomandibular disorder and lead to successful treatment for the patients with temporomandibular joint sounds.

• Journal of Biomedical Engineering Research
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• v.31 no.3
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• pp.199-209
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• 2010

The locking compression plates-distal femur(LCP-DF) are being widely used for surgical management of the extra-articular complex fractures of the distal femur. They feature locking mechanism between the screws and the screw holes of the plate to provide stronger fixation force with less number of screws than conventional compression bone plate. However, their biomechanical efficacies are not fully understood, especially regarding the number of the screws inserted and their optimal configurations. In this study, we investigated effects of various screw configurations in the shaft and the condylar regions of the femur in relation to structural stability of LCP-DF system. For this purpose, a baseline 3-D finite element (FE) model of the femur was constructed from CT-scan images of a normal healthy male and was validated. The extra-articular complex fracture of the distal femur was made with a 4-cm defect. Surgical reduction with LCP-DF and bone screws were added laterally. To simulate various cases of post-op screw configurations, screws were inserted in the shaft (3~5 screws) and the condylar (4~6 screws) regions. Particular attention was paid at the shaft region where screws were inserted either in clustered or evenly-spaced fashion. Tied-contact conditions were assigned at the bone screws-plate whereas general contact condition was assumed at the interfaces between LCP-DF and bone screws. Axial compressive load of 1,610N(2.3 BW) was applied on the femoral head to reflect joint reaction force. An average of 5% increase in stiffness was found with increase in screw numbers (from 4 to 6) in the condylar region, as compared to negligible increase (less than 1%) at the shaft regardless of the number of screws inserted or its distribution, whether clustered or evenly-spaced. At the condylar region, screw insertion at the holes near the fracture interface and posterior locations contributed greater increase in stiffness (9~13%) than any other locations. Our results suggested that the screw insertion at the condylar region can be more effective than at the shaft during surgical treatment of fracture of the distal femur with LCP-DF. In addition, screw insertion at the holes close to the fracture interface should be accompanied to ensure better fracture healing.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.4
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• pp.229-239
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• 2009

The purpose of this study is to evaluate the change in condylar position, width, and angle before and after orthognathic surgery using 3-dimensional computed tomograph. Pre and posterative 3-D CT was taken on 38 patients and through axial, frontal, sagittal measurements and by 3-dimensional reconstruction, the changes in condylar postion, mandibular width and angle were analyzed and others such as the difference in gender, operation and fixation method, setback length and in relation with temporomandibular disorders were done together too. The results were as follows: The inward rotation of condyle in axial condylar angle, the forward movement of right condyle in sagittal anterior-posterior distance, the superior movement of both condyles in sagittal superior-inferior distance, the decrease in gonial angle, the increase in mandibular width, the decrease in distance between the axial coronoid process distance and the increase in the frontal intercondylar distance were statistically significant. There were no statistically significant changes in gender difference, however in the difference in operation method, change in the gonial angle was observed and there was more change in bilateral sagittal split osteotomy group compared to two-jaw surgery group. In the difference in fixation method, the decrease in axial coronoid process distance and the change in sagittal anterior-posterior distance were statistically significant. In the difference in setback, the increase in setback didn't relate directly with the increased change in condyle position. In the relation with temporomandibular disorder, changes in left axial condylar angle and axial coronoid process distance were statistically significant. Changes in condylar position could be observed after the orthognathic surgery but it doesn't seem to have much of a clinical importance. The orthognathic surgery is effective in decreasing the mandibular angle, and it is not related with the temporomandibular disorder.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.21 no.2
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• pp.353-365
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• 1991

The author analyzed and compared tomographs with lateral oblique transcranial radiographs of 60 temporomandibular joints from 30 asymptomatic young adults. The results were as follows: 1. The mean height & width of condylar head were 6.82±1.99㎜, 11.98±1.28㎜ in tomographs and 5.41±0.79㎜, 10.67±1.28㎜ in transcranial radiographs. The mean height of articular fossa was 10.19±1.60㎜ in tomographs and 8.44±1.65㎜ in transcranial radiographs. 2. The mean width of articular fossa was 20.71 ±2.98㎜ in tomographs and 17.47±2.58㎜ in transcranial radiographs. There were significant differences in both the height and the width of articular fossa between two radiographic techniques (P<0.01). 3. In centric occlusion, the superior joint spaces were 4.28±1.09㎜, 4.18±1.28㎜, the anterior joint spaces were 2.84±1.02㎜, 2.53±0.72㎜, the posterior joint spaces were 3.11±1.19㎜, 2.66±0.89㎜ in tomographs and transcranial radiographs respectively. There were significant differences in right posterior joint spaces (P<0.05), and posterior joint spaces (P<0.05) between two radiographic techniques. 4. The condylar position in articular fossa was displaced posteroinferiorly (-0.35±4.40㎜ posteriorly, -1.55±1.24㎜ inferiorly) in tomographs and anteroinferiorly (0.45±3.77㎜ anteriorly, -1.29±1.26㎜ inferiorly) in transcranial radiographs with 1 inch opening. In maximum opening, it was displaced anteroinferiorly (5.39±3.63㎜ anteriorly, -1.22±1.67㎜ inferiorly) in tomographs and anteroinferiorly (6.35±4.00㎜ anteriorly, -0.55 ±1.98㎜ inferiorly) in transcranial radiographs. There was significant difference in superoinferior positions of both condyles with maximum opening between two radiographic techniques (P<0.05).

• The korean journal of orthodontics
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• v.47 no.5
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• pp.277-288
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• 2017

Objective: Treating Class II subdivision malocclusion with asymmetry has been a challenge for orthodontists because of the complicated characteristics of asymmetry. This study aimed to explore the characteristics of dental and skeletal asymmetry in Class II subdivision malocclusion, and to assess the relationship between the condyle-glenoid fossa and first molar. Methods: Cone-beam computed tomographic images of 32 patients with Class II subdivision malocclusion were three-dimensionally reconstructed using the Mimics software. Forty-five anatomic landmarks on the reconstructed structures were selected and 27 linear and angular measurements were performed. Paired-samples t-tests were used to compare the average differences between the Class I and Class II sides; Pearson correlation coefficient (r) was used for analyzing the linear association. Results: The faciolingual crown angulation of the mandibular first molar (p < 0.05), sagittal position of the maxillary and mandibular first molars (p < 0.01), condylar head height (p < 0.01), condylar process height (p < 0.05), and angle of the posterior wall of the articular tubercle and coronal position of the glenoid fossa (p < 0.01) were significantly different between the two sides. The morphology and position of the condyle-glenoid fossa significantly correlated with the three-dimensional changes in the first molar. Conclusions: Asymmetry in the sagittal position of the maxillary and mandibular first molars between the two sides and significant lingual inclination of the mandibular first molar on the Class II side were the dental characteristics of Class II subdivision malocclusion. Condylar morphology and glenoid fossa position asymmetries were the major components of skeletal asymmetry and were well correlated with the three-dimensional position of the first molar.

• Imaging Science in Dentistry
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• v.31 no.4
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• pp.227-233
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• 2001

Purpose: The purpose of this study was to investigate the apoptosis induction in tissues constituting the craniofacial region of growing rat by irradiation. Materials and Methods: The submandibular gland, brain, articular cartilage of condylar head, and calvarium were extracted from 20-day-old rats irradiated 10 Gy. Apoptosis of each tissue was examined by DNA fragmentation and estimated quantitatively using apoptotic index on TUNEL assay. Apoptotic index of each tissue was calculated by the equation for apoptotic cells/total cells × 1,000 on the images of confocal laser scanning microscopy. Apoptotic index was analyzed statistically according to the time lapse after irradiation on the tissues. Results : In the submandibular gland, apoptotic index was significantly increased from 6 hours after irradiation showing the highest value at 12 hours and decreased to the control level at 3 days after irradiation. In the brain, apoptotic index was abruptly reached to the maximum value at 6 hours after irradiation and decreased to the control level at 4 days after irradiation. Articular cartilage and calvarium showed no or little apoptotic signals. The results obtained by the apoptotic index accorded with that of DNA fragmentation. Conclusion : Radiation was closely related with the apoptosis of submandibular gland and brain but, not related with the apoptosis of the articular cartilage of condylar head and calvarium. The changes induced by radiation of the hard tissues would not be explained by apoptosis.