• The korean journal of orthodontics
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• v.13 no.2
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• pp.155-163
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• 1983

Many different appliances have been used to move teeth or to attempt to inhibit or stimulate growth of the jaws. Especially, Orthopedic force was used to apply a constant force on the mandible. Various orthopedic forces bring the changes of surrounding tissue, growth and development on the mandibular joint. Author carried out this study to find the histological changes of the mandibular joint in rats when the mandible applied posterior displacement. For the purpose of this study, $009\times036inch$ closed coil spring and 030inch orthopedic wire were used between the post occipital region and the chin region in order to render the orthopedic forces, posteriorly. The experimental animals vu. used 1 month old (GroupI), 3 months old (Group II), and 12 months old (Group III) rats. Following results were obtained; 1. At the beginning of the experimental Group I, there were predominant increment of Cartilage layer in the posterior parts of condylar head. Especially, the mature chondrocyte zone was increased. 2. In the experimental Group II, the chondroblastic zone was decreased while it showed slightly increased mature cartilage zone. 3. In the experimental Group III, the mature chondrocyte zone was disappeared gradually and there was a tendency to reduce the endochondral bone formation in condylar head. 4. After 30 days of experimental Group I and in experimental Group II, there was a tendency to decrease the immature cellular zone in the glenoid fossa by pressure. 5. There were no histological changes in the articular disc by pressure.

• Clinics in Shoulder and Elbow
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• v.17 no.4
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• pp.185-189
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• 2014

We report a case of intramuscular hemangioma in the subscapularis muscle and the resulting impairment of shoulder function in an adult patient. A nineteen-year-old female complained of shoulder pain and the development of a mass in the absence of previous trauma. Physical examinations, including lift-off and belly-press tests, showed abnormality. X-ray showed multiple calcifications in the front of the scapula. Magnetic resonance imaging showed a soft-tissue mass occupying almost the entire intramuscular portion of the subscapularis muscle. An arthroscopic examination excluded the possibility of a joint invasion, after which the entire mass was successfully removed by open excision. The displacement of the subscapularis by the mass was relieved after the surgery. Pathological diagnosis of the tissue confirmed a cavernous hemangioma. Both shoulder pain and function was improved after operation. There was no evidence of recurrence even at the 2-year follow-up. Rare forms of hemangioma adjacent to the shoulder joint could be successfully managed with surgical excision. Differential diagnosis, such as synovial chondromatosis, pigmented villo-nodular synovitis, and malignant sarcoma, should also be considered.

• Journal of the korean academy of Pediatric Dentistry
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• v.10 no.1
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• pp.35-45
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• 1983

This study was undertaken to evaluate the pulpal responses to the intermediate restorative materials such as Zinc phosphate cement, Polycarboxylate cement, IRM (zinc oxide eugenol cement), Dycal, Life, Cresatin, and Fluoride in caivties which were cut with high speed instrument. 5 dogs were used as experimental animals and devided into 8 groups. The intervals of observaobservation ranged 3 days, 1, 3, 4, 8 weeks after experiment respectively. The specimens were fixed with 10% formalin and decalcified in 5% nitric acid. All slides were stained with hemtoxylin-eosin and examined histopathologically. The results were as follows: 1. In control group, severe vacuolar degeneration and atrophy of odontoblasts were seen in 3 days, hemorrhage and congestion continued until 8 weeks. Necrosis of odontoblastic layer was seen in zinc phosphate cement group and polycarboxylate cement group. 2. In dycal group, vacuolar degeneration and atrophy of odontoblast were not seen. but in Life group, these were seen in 3 days and partially continued until 3 weeks. In 4 weeks, regeneration of odontoblast was occured. 3. In Crcsatin group, there was no pathosis except odontoblastic displacement. In Fluoride group, vacuolar degeneration of odontoblast was seen and soon disappeared. As compared with control group, pathological change of the pulp tissue in experimental group were decreased after amalgam restoration.

• Korean Journal of Veterinary Service
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• v.29 no.4
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• pp.507-511
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• 2006

Acanthomatous epulis is a malignant form of gingival tumor. This is a case of epulis affecting a four-year old, intact, female Maltese dog raised as indoor pet in Iksan city. Clinical examination showed an enlarged palpable mass along the rostral maxillary gingiva. Section of the excised mass showed epithelial overgrowth and expansion from the basal portions through the tissue stroma. Post-surgical radio-graph showed displacement of the first and second maxillary incisors. Histochemical staining showed strongly positive reaction to epithelial marker cytokeratin and moderately positive reaction to connective tissue marker vimentin. This case was diagnosed as a form of maxillary gingival acanthomatous epulis. Routine clinical oral examination is suggested.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.28 no.2
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• pp.136-142
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• 2006

Temporomandibular joint(TMJ) disorders have characteristic clinical findings such as pain, joint sound, and abnormal jaw function. With the rapid progress in TMJ imaging techniques, magnetic resonance imaging(MRI) especially provides the clinician and researcher with the ability to evaluate TMJ disorders(effusion, anterior disk displacement) and the hard and soft tissue of the TMJ. In order to manage the internal derangement of TMJ such as anterior disk displacement, the so-called appliance therapy is commonly used. This technique became the treatment of choice before surgical intervention by many practitioners. The purpose of the present study was to evaluate and determine the efficacy of anterior repositioning splint by means of the change of the position of the disk through pre- and post-treatment MRI. MRI and clinical symptom were carefully recorded in TMJ disorder patients. The relationship between TMJ symptoms such as pain, clicking sound, and disk displacement and effusion in MRI were analyzed. Then, splint therapy was applied for 3 months according to our protocol; at day 1, patients should wear 24 hours, in order to accomodate the splint and then, wearing time is reduced to 12 hours per day for one month. During next 2 months, it is tapered to 8 hours per day according to the evaluation of the clinical symptoms. Post-treatment MRI was obtained after 3 month protocol. This treatment strategy improved the clinical symptoms of TMJ disorder, and effusion and articular disk position showed a significant change. In conclusion, a treatment modality using an anterior repositioning splint therapy is an appropriate method for temporomandibular disorder patients.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.2
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• pp.199-215
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• 1990

This study was to analyze the stress distribution of implant and supporting tissue in $Br{\aa}nemark$ osseointegration implant. The analysis has been conducted by using the axisymmetric finite element method and type of model according to crown material. Tests have been performed at 1 kg load on central fossa of crown portion. Each type of model was designed differently according to crown material. 1) Porcelain fused to metal crown(Model A) 2) Composite resin veneered crown(Model B) 3) Acrylic resin veneered crown(Model C) 4) Type III gold crown(Model D) The displacements and stresses of implant and supporting structures were analyzed to investigate the influence of the type of crown material. The results were obtained as follows : 1. Displacement of implant was shown uniformly downward displacement in all models and abutments were observed distally downward displacement. 2. In supporting tissues, stress was concentrated on the crest of compact bone and the spongy bone below implant. 3. The PFM and the type III gold crown showed the largest concentration of stress at the crest of compact bone and the spongy bone below implant, respectively. Acrylic resin artificial teeth and composite resin veneered crown indicated almost the same distribution of stress. 4. The gold screw, the abutment screw and the top of abutment showed the concentration of stress in implants of every model.

• Restorative Dentistry and Endodontics
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• v.26 no.6
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• pp.464-484
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• 2001

When restoring a tooth, the dentist tries to choose the ideal material for existing situation. One criterion that is considered is its suitability for restoring coronal strength. As more tooth structure is removed, the cusps are weakened and susceptible to fracture. Further, this increased deformation may cause the formation of intermittent gaps at the margin between the hard tissue and the restoration, facilitating marginal leakage. The improvements in ceramic materials now make it possible for alternatives to amalgams, composites, and cast metal to be of offered for posterior teeth. Of the materials used, ceramics most closely approximates the properties of enamel. The introduction of computer-aided design/computer-aided manufacture(CAD/CAM) systems to restorative dentistry represents a major technological breakthrough. It is possible to design and fabricate ceramic restorations at a single appointment. Additionally, CAD/CAM systems eliminate certain errors and inaccuracies that are inherent to the indirect method and provide an esthetic restoration. The aim of this investigation was to study the loading characteristics of CAD/CAM ceramic inlay and to compare the stress distribution and displacement associated with different designs of cavity(the isthmus width and cavity depth). A human maxillary left first premolar was prepared with standard mesio-occlusal cavity preparation, as recommended by the manufacturer Ceramic inlay was fabricated with CEREC 2 CAD/CIM equipment and cemented into the prepared cavity. Three dimensional model was made by the serial photographic method. The cavity width was varied $\frac{1}{3}$, $\frac{1}{2}$ and $\frac{2}{3}$ of intercuspal distance between buccal and lingual cusp tip. The cavity depth was varied 1.5mm and 2.3mm. So six models were constructed to simulate six conditions. A point load of 500N was applied vertically onto the first node of the lingual slope from the buccal cusp tip. The stress distribution and displacement were solved using ANSYS finite element program(Swanson Analysis System). (omitted)

• The Journal of Advanced Prosthodontics
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• v.13 no.1
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• pp.55-64
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• 2021

PURPOSE. To investigate the biomechanical effect of marginal bone resorption (MBR) on the mandibular mini implant (MI)-retained overdenture (MI-OD) on the edentulous model. MATERIALS AND METHODS. The experimental mandibular edentulous model was modified from a commercial model with 2 mm thick artificial soft tissue under denture base. Two MIs (Φ2.6 mm × 10 mm) were bilaterally placed between the lateral incisor and the canine area and attached with magnetic attachments. Three groups were set up as follows: 1) alveolar bone around the MI without MBR (normal group), 2) with MBR to 1/2 the length of the implant (resorption group), and 3) complete denture (CD) without MI (CD group). Strain around the MI, pressure near the first molar area, and displacement of denture were simultaneously measured, loading up to 50 N under bilateral/unilateral loading. Statistical analysis was performed using independent-samples t test and one-way ANOVA (α=.05). RESULTS. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure in CD was higher than in MI-ODs (P<.05), while there was no statistical difference between the normal and resorption group (P>.05). Similarly, the CD demonstrated a greater displacement of the denture base than did the MI-ODs during bilateral and unilateral loadings (P<.05). CONCLUSION. The strain around the MI with MBR was approximately 1.5 times higher than that without MBR. The pressure on posterior alveolar ridge and denture displacement of MI-ODs significantly decreased compared to CDs, even when MBR occurs. Bilateral balanced occlusion was recommended for MI-ODs, especially when MBR occurred.

• 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 Journal of Korean Academy of Prosthodontics
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• v.56 no.1
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• pp.64-69
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• 2018

Odontogenic myxoma of the jaws is a rare benign odontogenic tumor. In this case, a 61-year-old male patient had a chief complaint about maxillary anterior gingival mass and excisional biopsy result confirmed odontogenic myxoma. The clear acrylic resin custom tray was designed to minimize displacement of flabby tissue which remained after the surgery. Neutral zone and external impression technique could provide satisfactory result in terms of denture stability and retention during jaw relation record and wax denture try-in procedure. This clinical report describes fabrication of complete dentures for a patient with odontogenic myxoma in regard to flabby tissue and neutral zone.