• Clinics in Shoulder and Elbow
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• 제9권2호
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• pp.207-210
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• 2006

We presented a case of posteriorly displaced fracture of the distal clavicle in Child. The closed reduction was failed due to posteriorly displaced proximal fragment and interpositon of trapezius muscle and periosteum. We found that periosteal sleeve and coracoclaviclar ligament and acromioclavicular ligament was intact. The open reduction should be considered for the treatment of the irreducible posteriorly displaced fracture of the distal clavicle in child.

• 대한치과교정학회지
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• 제22권2호
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• pp.475-481
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• 1992

The purpose of this study was to examine the displacement of glenoid fossa during growth, and to investigate the relationship between the displacement of glenoid fossa and mandible. Pretreatment and posttreatment lateral cephalograms of 41 patients (male : 13, female : 28) were obtained from the orthodontic clinics of Wonkwang university hospital and were analized in terms of the position of articulare and mandible and statistically. The obtained results were as follows, 1. Aritculare was displaced posteriorly and inferioly during craniofacial growth and development. 2. The more posteriorly articulare displaced, the less anteriorly pogonion displaced, but the more inferiorly menton displancd. 3. The more posteriorly or inferiorly articulare was located, the more inferiorly menton displaced, and the more posteriorly articulare was located posteriorly, the less cant of the mandibular plane.

• 대한치과교정학회지
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• 제26권6호
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• pp.691-703
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• 1996

Three-dimensional finite element model was made from adult skull to find desirable direction of retraction force to treat skeletal class II malocclusion. The retraction force of 400g was applied to the first molar. The direction of the force application was $23^{\circ}$ downward, parallel, $23^{\circ}$ upward and $45^{\circ}$ upward to the occlusal plane. The stress distribution and the displacement within the maxilla were analyzed by three-dimensional finite element method. The findings obtained were as follows: 1. Maxillary first molar was displaced posteriorly and inferiorly in $23^{\circ}$ downward, parallel, $23^{\circ}$ upward retraction but it was displaced posteriorly and superiorly in $45^{\circ}$ upward retraction. 2. ANS, A point and prosthion were moved posteriorly and inferiorly and pterygomaxillary fissure was moved posteriorly and superiorly. Clockwise rotation of maxilla occurred when retraction force was applied. 3. The degree of clockwise rotation of maxilla was greatest when the force was applied $23^{\circ}$ upward to the occlusal plane and was least when the force was applied $23^{\circ}$ downward to the occlusal plane. 4. Large tensile stress appeared in maxillary first molar and alveolar bone and the infraorbital region of maxilla when the force was applied $23^{\circ}$ downward to the occlusal plane. Tensile stress was smaller as the direction of force move upward. 5. Large compressive stress was appeared in maxillary first molar and infraorbital region in $45^{\circ}$ upward case and large compressive stress occurred in the posterior part of maxilla as the retraction force was upward.

• 대한치과보철학회지
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• 제33권3호
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• pp.413-439
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• 1995

The purpose of this study was to evaluate the stress distribution developed in the supporting structures by mandibular distal extension removable partial dentures with 2 different direct retainer designs and with or without indirect retainer and abutment splinting. The examined direct retainers on the second bicuspid abutment tooth were Akers clasp and RPA clasp, the indirect retainer was located on the mesial fossa of the first bicuspid, and the first and second bicuspid were splinted in case of tooth splinting. Total 8 cases were compared and analyzed with 3-dimensional finite element method. 150N were applied vertically on the artificial teeth of the removable partial denture, and then stress distribution patterns were analyzed and compared. The results were as follows : 1. The forces transmitted to the abutment tooth were primarily from the occlusal rests. 2. The abutment tooth was displaced distally when the force was applied. The compressive stress was observed at the distal root surface of the abutment tooth and the tensile stress, at the mesial root surface. 3. The denture base was displaced posteriorly and inferiorly when the force was applied. At the more distal portion of the denture base, the greater displacement was observed.And the anterior portion of the major connector was displaced superiorly. 4. The occlusal rest placed on the distal part of the abutment tooth tended to tip the tooth more posteriorly than did one on the mesial part of that tooth. 5. Severe superior displacement was observed at the anterior portion of the major connector in case of removable partial dentures without indirect retainer. 6. In case of tooth-splinting, the stress was distributed through all the root surface of both abuments. In case of no tooth-splinting, the stress was concentrated on the distal root surface of the primary abutment.

• 대한관절경학회지
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• 제10권2호
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• pp.187-191
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• 2006

전방 십자 인대 재건술 후 대퇴 간섭 나사가 후방 구획으로 전위된 예는 극히 드물게 보고되고 있다. 이는 대개의 경우 기계적인 증상을 일으키므로 수술적인 제거술이 요구된다. 그러나 나사를 관절경적으로 제거하는 것은 기술적으로 어려운 술기이며 특히, 나사가 후방 구획으로 이동되었으나 전방 십자 인대가 잘 유지되어 있는 경우, 혹은 나사 주위가 막으로 둘러 쌓여 있을 경우 관절경적 제거는 더욱 어렵다. 저자들은 전방 십자 인대 재건술 후 재건 인대가 생착된 11년 후에 대퇴 간섭 나사가 후방 구획으로 전위된 1예를 보고하고자 한다. 저자들은 경우 가장 힘든 후방 구획에 위치한 전위된 대퇴 간섭 나사를 전방십자인대 이식건의 손상 없이 후방 경격막 도달법을 이용한 관절경적으로 제거하여 좋은 결과를 얻었기에 문헌고찰과 함께 보고하고자 한다.

• 대한치과교정학회지
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• 제50권2호
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• pp.129-135
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• 2020

Objective: This study aimed to evaluate the immediate effects of mandibular posterior displacement on the pharyngeal airway space (PAS) by using cephalometric evaluations and to investigate how the surrounding structures are schematically involved. Methods: In this retrospective study, 38 subjects with functional Class III malocclusion and two lateral cephalograms were selected. The first lateral cephalogram was taken with the mandible in the habitual occlusal position, and the second in anterior edge-to-edge bite. Paired t-test was used to analyze changes in the PAS, hyoid bone, tongue, and soft palate, followed by mandibular posterior displacement. Pearson's correlation analysis was used to determine the relationship between the amount of mandibular posterior displacement and other variables. Results: A statistically significant decrease was observed in the PAS following mandibular posterior displacement. Along with mandibular posterior displacement, the tongue decreased in length (p < 0.001) and increased in height (p < 0.05), while the soft palate increased in length, decreased in thickness, and was posteriorly displaced (p < 0.001). The hyoid bone was also posteriorly displaced (p < 0.05). There was no correlation between the amount of mandibular posterior displacement and the measured variables. Conclusions: The PAS showed a statistically significant decrease following mandibular posterior displacement, which was a consequence of retraction of the surrounding structures. However, there were individual variances between the amount of mandibular posterior displacement and the measured variables.

• 대한치과교정학회지
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• 제21권1호
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• pp.53-76
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• 1991

The study was designed to analyse the reorganization of the rabbit TMJ meniscus which was anteriorly displaced by surgery. The author compared the anteriorly displaced groups with control group. After surgical opening of the left rabbit TMJ space, cut the posterior attachment of the meniscus, and pushed it under the undercut area of the condyle head. Experimental groups were sacrificed by 1, 2, 4, 8 weeks after surgery. The samples were analysed with light microscope under T-B stain and electron microscope. The results were as follows: 1) The rabbit TMJ meniscus consisted of thick anterior and posterior band running different way, and comparative thin intermediate band runining antero-posteriorly. 2) Round oval shape chondrocyte-like cells were imbeded between the collagen fiber bundles and composed of proteoglycan granules, that showed metachromasia with toluidine blue, around the cell matrix. 3) Type II collagen fiber bundles in experimental group occured degenerative changes in organic patterns at 8 weeks, but those of type I collagen fiber bundles sustained longer, 4) The typical fibrocartilage of the rabbit TMJ meniscus was changed into fibrotic mode in process of time and showed the degenerative changes, which contained hyperplasia, calcification, resorption and hyalinization in the connective tissue. 5) The hyperplastic change of the synovial membrane in 4 week group and transitional change from fibrocyte to chondrocyte in cell type in 8 week group were observed. 6) The diameters of collagen fibers were diminished with the degenerative changes, the shape of the fibers became wavier and more nonorganic in running pattern and fiber bundle spaces widened.

• Journal of Oral Medicine and Pain
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• 제41권3호
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• pp.137-143
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• 2016

Posterior disk displacement (PDD) of the temporomandibular joint (TMJ) is a rare condition and most descriptions of TMJ PDD are about the adhesion of superior TMJ in which the position of disk is relatively posterior to anteriorly translated condyle in open mouth position. However, there have been reports about truly posteriorly positioned disk to the condyle in closed mouth position. This type of PDD has been classified into three subtypes-thin flat disk type, grossly posterior displaced disk type, and perforated disk type. Here, we report two rare cases of TMJ PDD, one with thin flat disk and one with perforated disk. Its possible etiology, pathogenetic mechanisms, related signs and symptoms, differential diagnoses, and treatments were reviewed and discussed.

• Journal of Trauma and Injury
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• 제31권2호
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• pp.112-116
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• 2018

Calcaneal fractures are quite often seen in patients with axial loading injury. In the tongue-type of calcaneusal fractures or tuberosity avulsion fractures, bone fragments are often superiorly and posteriorly displaced, because of the insertion of the Achilles tendon and pull of the gastroc-soleus complex. The Ddisplaced bone fragment compresses the soft tissues, leading tothat makes skin necrosis. To prevent further soft tissue injury, early recognition of the injury by the emergency physician and immediate orthopedic consultation is needed.

• 치과방사선
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• 제21권2호
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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).