• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.19 no.1
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• pp.7-18
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• 1989

The authors analyzed the clinical findings, radiological findings and their correlations in the temporomandibular joint disorders. The results were as follows: 1. The most prevalent age group was in the first decade, then the second decade and the third decade. Female were more common with a ratio of 3.4:1. 2. The most common clinical findings was the pain on open mouth position (42.3%), then came the clicking and limitation of mouth opening. 3. The most common bone change on the condyle side was the erosion, then came the flattening, the osteopyte and the sclerosis in that orders. 4. In the case of the crepitus, the coarse crepitus showed more radiological change than the fine crepitus. The 27% of the patients with crepitus showed the bone change and the patients with crepitus showed more bone change than any other clinical symptoms. 5. In the case of the mouth opening limitation, the evaluation of the translatory movement by transcranial projection was in accordance with the clinical evaluation. 6. The correlation between the clinical symptom and the condylar position within the mandibular fossa was not present and in the case of diagnosis of disc displacement, the transcranial projection seemed not to be able to substitute for the arthrography. Radiographically, the most prevalent age group which showed the bone change was in the first, the second and the third decade. And the bone change seemed to have no relationship with aging.

• The Journal of Korean Academy of Prosthodontics
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• v.25 no.1
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• pp.119-135
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• 1987

For the determination of instantaneous centre of rotation in the mandibular movement, the habitual opening path was recorded on the sagittal tracing plate by a Gnathorecorder attached on the lower anterior teeth which was designed for this study. The opening path was demonstrated mathematically and the instantaneous centre of rotation in the opening path were calculated and plotted by computer programs, and then a computer graphic movement of the mandible was obtained according to the opening path. The hinge path of posterior border movement was graphied by the Gnathorecorder as well and demonstated mathematically. This hinge path was compared with the same obtained by Visitrainer to prove a reliability of the Gnathorecorder. The results obtained from this study were as follows. 1. The habitual opening path and hinge path obtained from the Gnathorecorder movement were expressed mathematically as follows: $y=0.11x^2-0.66x+3.09$ (equation of opening path), $y=0.04x^2+0.21x+3.71$ (equation of hinge path), and a kinematic hinge axis was not shown in the equation of kings path. 2. The early habitual opening movement of the mandible demonstrated almost a straight opening path or an arc motion with the larger radius and it's centre of rotation moved parallelly in the more rear and lower position than a kinematic hinge axis. 3. Instantaneous centre of rotation occured along with the translation of the condyle, and mandible was rotated around an axis in the close to the maximum opening and then moved toward the forward and upward position. 4. There were some similarities between the articular eminence and the movement pattern of a special point which was the kinematic hinge axis.

• The korean journal of orthodontics
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• v.43 no.4
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• pp.168-177
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• 2013

Objective: In this study, we aimed to examine the relationship between chin deviation and the positional and morphological features of the mandible and to determine the factors that contributed to chin deviation in individuals with a unilateral cleft lip and palate (UCLP). Methods: Cone-beam computed tomography (CBCT) images of 28 adults with UCLP were analyzed in this study. Segmented three-dimensional temporomandibular fossa and mandible images were reconstructed, and angular, linear, and volumetric parameters were measured. Results: For all 28 individuals, the chin was found to deviate to the cleft side by 1.59 mm. Moreover, among these 28 individuals, only 7 showed distinct (more than 4 mm) chin deviation, which was toward the cleft side. Compared to the non-cleft side, the mandibular body length, frontal ramal inclination, and vertical position of the condyle were lower and inclination of the temporomandibular fossa was steeper on the cleft side. Furthermore, the differences in inclination of the temporomandibular fossa, mandibular body length, ramus length, and condylar volume ratio (non-deviated/deviated) were positively correlated with chin deviation. Conclusions: UCLP individuals show mild chin deviation to the cleft side. Statistical differences were noted in the parameters that represented positional and morphological asymmetries of the mandible and temporomandibular fossa; however, these differences were too small to indicate clinical significance.

• Journal of Korean Neurosurgical Society
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• v.55 no.5
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• pp.284-288
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• 2014

A rare case of atlantoaxial rotatory subluxation occurred after pediatric cervical spine surgery performed to remove a dumbbell-shaped meningioma at the level of the C1/C2 vertebrae. This case is classified as a post-surgical atlantoaxial rotatory subluxation, but has a very rare morphology that has not previously been reported. Although there are several reports about post-surgical atlantoaxial rotatory subluxation, an important point of this case is that it might be directly related to the spinal cord surgery in C1/C2 level. On day 6 after surgery, the patient presented with the Cock Robin position, and a computed tomography scan revealed a normal type of atlantoaxial rotatory subluxation. Manual reduction was performed followed by external fixation with a neck collar. About 7 months after the first surgery, the subluxation became severe, irreducible, and assumed an atypical form where the anterior tubercle of C1 migrated to a cranial position, and the posterior tubercle of C1 and the occipital bone leaned in a caudal direction. The pathogenic process suggested deformity of the occipital condyle and bilateral C2 superior facets with atlantooccipital subluxation. A second operation for reduction and fixation was performed, and the subluxation was stabilized by posterior fixation. We encountered an unusual case of a refractory subluxation that was associated with an atypical deformity of the upper spine. The case was successfully managed by posterior fixation.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.6
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• pp.545-551
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• 2005

Purpose: The effect of orthognathic surgery on the temporomandibular dysfunction has been controversial. The purpose of this study is to prove statistically that early removal of fixation plate at postoperative 2 weeks with active exercise of mouth opening could relieve preoperative temporomandibular dysfunction and reposition of temporomandibular joint. Patients and Methods: All 28 subject patients underwent mandibular setback with BSSRO in Kyunghee medical center by one surgeon. The fixation plates used for rigid fixation were removed at postoperative 2 weeks and we had the patients excercise active mouth opening with intermaxillary rubber rings for the guiding proper postoperative occlusion. Temporomandibular symptoms were checked and radiographs were taken before surgery, within a month after surgery, six to twelve months after surgery respectively. Results: The temporomandibular dysfunction symptoms were relieved after the surgery and the condyle was displaced inferior-posteriorly immediate after surgery and repositioned toward its original position during follow-up periods. Conculusion: Orthognathic surgery may benefit temporomandibular joint dysfunction by obtaining a postoperative stable occlusion and more physiologic neuromuscular function. The early removal of fixation plates after BSSRO could reposition the temporomandibular joint to physiologic position and relieve the symptoms of temporomandibular dysfunction by permitting movement of proximal segment.

• Journal of the Korean Arthroscopy Society
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• v.9 no.1
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• pp.56-59
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• 2005

Trans-posterior septal posterior arthroscopic portals are useful in performing arthroscopic diagnosis and treatment of the lesions located in posterior aspect of knee joints. Except inferior surface of posterior horn of lateral meniscus, we easily observed entire lateral compartment, especially inferior surface of anterior horn and lateral tibial condyle by figure of 4 position through posteromedial trans-posterior septal arthroscopic portal. And it was possible to obtain visual field from posterior aspect and we could use anteromedial and anterolateral portals for instrumentation without clouding. So, this procedure may be useful in performing surgery of lateral compartment especially, anterior aspect in the knee joints.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.330-338
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• 2022

For edentulous patients with unstable mandibular movements and abnormal facial features due to condylar fractures and morphological abnormalities, it is important to find a stable mandibular position. In this case, the patient's facial improvement, mandibular movement stability, and denture stability were improved by using flat table treatment dentures. In addition, computer-aided design/manufacturing (CAD-CAM) technology was used in denture fabrication to maintain the vertical dimension and lip support of flat table treatment dentures, we report good results in improving the patient's discomfort.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.2
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• pp.249-270
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• 1993

For understanding of anatomy, physiology, and diseases of human TMJ, it is required to evaluate quantitatively the movement of the disc and condyle head of mandible. The histologic section of cadaver TMJ were examined, and the magnification of the MR image and its details of anatomy were evaluated. And then a quantitative analytic method, by comparing the Sectograph and the MR image of vital human TMJ, was proposed. For this study, 15 subjects(Male, 24~35years) were selected from a prosthodontic examination randomly, and each subject’s five interocclusal rubber registration records were made on the ICP, and 5, 10, 15, and 20mmjaw opening positions. All subjects were radiographed with a Denar Quint Sectograph Image System(Denar Corp., USA), and imaged with a MRP-20EX MR Image System(0.2T, Permanent Magnet Type, Hitachi Medical Corp., Japan) using an 100mm diameter bilateral type surface coil. These images were traced on the acetate tracing paper, and analyzed In this study, the findings led to the following conclusions. 1. In comparison of the histologic section of autopsy specimen with the MR image at the same section, the size(dimension) of MR image was 70% of the real one. It was possible to recognize the shape of articular disc, anterior and posterior attachments, and adjacent soft tissues, because of the excellent reproducibility of anatomical structure. 2. When we compared the amount of joint space on MR image with that of joint space on sectograph, the amount of joint space on sectograph was significantly greater than that of joint space on MR image, except at the top of condylar head. 3. The position of minimum joint space on sectograph at intercuspal position didn't coincide with the middle position of articular disc on MR image, and was approximately in the anterior third of posterior band of articular disc. 4. The amount of condylar movement on MR image at opening movement was greater than that of articular disc movement. From Intercuspal position to 5mm jaw-opening movement, the condylar movement showed hinge one, and over the range 5mm jaw-opening it suggested hinge & translatory one. 5. In terms of area variation of articular disc measured on MR image in sagittal plane, the area of posterior band increased with increasing the amount of Jaw opening, but the area of anterior band decreased conversely.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.4
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• pp.245-256
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• 2001

The purpose of this study is to analyze the mechanical stress and displacement on the jaws during the simulated bilateral clenching task on the three-dimensional finite element model of the dentated skull with unilateral molar loss. For this study, the computed tomography(G.E.8800 Quick, USA) was used to scan the total length of human skull in the frontal plane at 2.0mm intervals. The fully assembled finite element model consists of the articular disc, maxilla, mandible, teeth, periodontal ligament and cranium. The FE model was used to simulate the bilateral clenching in intercuspal position. The loading condition was the force of the masseter muscle exerted on the mandible as reported by Korioth et al. degrees of freedom of the zygomatic region where the masseter muscle is attached were fixed as restraints. In order to reflect the actual action of the muscles force, the displacement of the region was attached where the muscle is connected to the temporal bone and restraint conditions were given values identical to values at the attachment region of the masticatory muscle but with the opposite direction of the reaction from when the muscle force is acted on the mandible. Although the mandible generally has higher displacement and von Mises stress than the maxilla, its mandibular corpus on the molar-loss side has a higher stress and displacement than the molar-presence side. Because the displacement and von Mises Stress was the highest on the lateral surface of mandibular corpus with molar loss, the stress level of the condyle on the molar-loss side is greater than that of the molar-presence side, which in turn caused the symphysis of the mandible to bend. In conclusion, the unilateral posterior bite collapse with molar loss under para-functional activities such as bruxism and clenching can affect the stress concentration on the condyle and mandibular corpus. It is therefore necessary to consider the biomechanical function of dento-skeleton under masticatory force while designing the occlusal scheme of restoration on alveolar bone with the posterior collapse.

• Journal of the Korean Society of Radiology
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• v.11 no.4
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• pp.253-262
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• 2017

In lateral projection imaging method of knee joint, a method that adjusts the incidence angle of central X-ray toward the head side to $5{\sim}7^{\circ}$ in true lateral position which is existing recommended is called imaging method A, Method of imaging the central X-ray perpendicular to the horizontal plane of the examination table toward the knee is called imaging method B, and a method in which the central X-ray is perpendicularly applied to the joints while the lateral side of the distal tibia is compensated by radiolucent materials is called as method C. After tests each imaging method to classified study subject respectively, the joint space distance and the distance between lateral and medial condyle of femur were measured and compared as the quantitative index from the three imaging methods. In addition, the convenience of each imaging method was confirmed through questionnaires to practician. According to the result of the quantitative index, there is no statistically significant difference in imaging method A and C(p>0.05). However, imaging method B showed a significant difference in both A and C(p<0.05). As a result of evaluating the convenience of the imaging method, imaging method A was relatively assessed lower in all items than imaging methods B and C, and as a small difference, imaging method B is assessed higher than C. In this study suggested new knee joint lateral projection imaging method, by using a simple support device, could describe joint space as not much different as existing recommended method without some complex process, and could increase convenience of the practician in the process of the imaging.