• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제40권3호
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• pp.123-129
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• 2014

Objectives: The aim of this study was to verify the concordance of the measurement values when the same cephalometric analysis method was used for two-dimensional (2D) cephalometric radiography and three-dimensional computed tomography (3D CT), and to identify which 3D Frankfort horizontal (FH) plane was the most concordant with FH plane used for cephalometric radiography. Materials and Methods: Reference horizontal plane was FH plane. Palatal angle and occlusal plane angle was evaluated with FH plane. Gonial angle (GA), palatal angle, upper occlusal plane angle (UOPA), mandibular plane angle (MPA), U1 to occlusal plane angle, U1 to FH plane angle, SNA and SNB were obtained on 2D cephalmetries and reconstructed 3D CT. The values measured eight angles in 2D lateral cephalometry and reconstructed 3D CT were evaluated by intraclass correlation coefficiency (ICC). It also was evaluated to identify 3D FH plane with high degree of concordance to 2D one by studying which one in four FH planes shows the highest degree of concordance with 2D FH plane. Results: ICCs of MPA (0.752), UOPA (0.745), SNA (0.798) and SNB (0.869) were high. On the other hand, ICCs of gonial angle (0.583), palatal angle (0.287), U1 to occlusal plane (0.404), U1 to FH plane (0.617) were low respectively. Additionally GA and MPA acquired from 2D were bigger than those on 3D in all 20 patients included in this study. Concordance between one UOPA from 2D and four UOPAs from 3D CT were evaluated by ICC values. Results showed no significant difference among four FH planes defined on 3D CT. Conclusion: FH plane that can be set on 3D CT does not have difference in concordance from FH plane on lateral cephalometry. However, it is desirable to define FH plane on 3D CT with two orbitales and one porion considering the reproduction of orbitale itself.

• Journal of Periodontal and Implant Science
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• 제25권2호
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• pp.407-417
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• 1995

In order to evaluate the effect of platelet-derived growth factor(PDGF-BB) and guided tissue regeneration(GTR) technique on the regeneration of destructed periodontal tissue,intentional through-and-through furcation defects(4mm in height) were made on both mandibular 2nd and 4th premolars of 8 adult male dogs(30-40lb). Experimental group 1 was composed of the premolars that were treated by only topical application of PDGF-BB with 0.05M acetic acid without any barrier membrane. Experimental group 2 was composed of the premolars that were treated by GTR with expanded polytetrafluoroethylene membrane(ePTFE : Gore-tex periodontal material, USA). Experimental group 3 was composed of the premolars that were treated by GTR with ePTFE after topical application of PDGFBE. Control group was composed of the premolars that were treated by coronally positioned flap operation only without use of PDGF-BB and ePTFE membrane. All ePTFE membranes were carefully removed 4 weeks after regenerative surgery, and all experimental animals were sacrificed 8 weeks after regenerative surgery. The light microscopic findings were as follows ; (1) In experimental group 1, rapid new bone formation along the-root surface with multiple ankylosis and root resorption by multinucleated giant cells, and dense connective tissue in the central portion of the furcation defects were observed. (2) In experimental group 2, it was observed that the furcation defects were filled with newly formed bone, Sharpey's fibers were embedded into new cementum on root dentin of furcation fornix area, but the central portion and the area under furcation fornix were still filled with dense connective tissue. (3) In experimental group 3, the furcation defects were regenerated with newly formed dense bone and regular periodontal ligament with Sharpey's fibers embedded into newly formed cementum and bone underneath fornix area. (4) In control group, unoccupied space, apical migration of epithelium, dense infiltration of inflammatory cells in subepithelial connective tissue in relation to heavy plaque accumulation, and root resorption by inflammatory reaction were shown, but any new cementum formation on resorbed dentin surface could not be observed. The present study demonstrated that the combined therapy of PDGF-BB and GTR could enhance the regeneration of destructed periodontal tissue.

• The Journal of Advanced Prosthodontics
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• 제6권5호
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• pp.361-371
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• 2014

PURPOSE. In case of large horizontal discrepancy of alveolar ridge due to severe resorption, cantilevered crown is usually an unavoidable treatment modality. The purpose of this study was to evaluate the clinical criteria for the placement of the aforementioned implant crown. MATERIALS AND METHODS. The mandible model with 2 mm thick cortical bone and cancellous bone was fabricated from CT cross-section image. An external connection type implant was installed and cantilevered crowns with increasing offset of 3, 4, 5, 6, and 7 mm were connected. Vertical load and $30^{\circ}$ oblique load of 300 N was applied and stress around bone and implant component was analyzed. A total of 14 cases were modeled and finite element analysis was performed using COSMOS Works (Solid works Inc, USA). RESULTS. As for the location of the vertical load, the maximum stress generated on the lingual side of the implant became larger according to the increase of offset distance. When the oblique load was applied at $30^{\circ}$, the maximum stress was generated on the buccal side and its magnitude gradually decreased as the distance of the offset load increased to 5 mm. After that point, the magnitude of implant component's stress increased gradually. CONCLUSION. The results of this study suggest that for the patient with atrophied alveolar ridge following the loss of molar teeth, von-Mises stress on implant components was the lowest under the $30^{\circ}$ oblique load at the 5 mm offset point. Further studies for the various crown height and numbers of occusal points are needed to generalize the conclusion of present study.

• 대한치과의사협회지
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• 제58권7호
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• pp.404-411
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• 2020

This study reports the unusual complications of 22-year-old male who presented with sudden hearing loss after the right mandibular third molar extraction under local anesthesia with 3.6 ml of 2 % lidocaine. Total 8.75 mg of oral dexamethasone for 1 week immediately after extraction was prescribed in department of oral and maxillofacial surgery but hearing did not improve after 1 week. As referral to otolaryngology, total 600 mg of oral methylon and hyperbaric oxygen therapies were operated for 2 weeks. The hearing of patient was improved at 6 weeks after extraction but tinnitus was persisted even after 12 months. The reason and treatment were discussed with literature review, searching with the keywords ['hearing loss' AND ('dental' OR 'tooth extraction'OR'teeth extraction')] in PubMed and Google scholar at October 2019. Total five cases were reported after tooth extraction with local anesthesia. The sudden hearing loss could be associated with local anesthesia containing vasoconstrictors. Early steroid (extensive medication and intra-tympanic injection) and hyperbaric oxygen therapies were recommended within 2 weeks. As a proper treatment, hearing could be improved but other additional symptoms, such as tinnitus, dizziness, might be remained.

• 대한치과교정학회지
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• 제50권2호
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• pp.136-144
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• 2020

Hemifacial microsomia (HFM) patients may experience emotional withdrawal during their growth period due to their abnormal facial appearance. Distraction osteogenesis at an early age to improve their appearance can encourage these patients. Some abnormalities of the affected side can be overcome by distraction osteogenesis at an early age. However, differences in the growth rate between the affected and unaffected sides during the rest of the growth period are inevitable due to the characteristics of HFM. Therefore, re-evaluation should be performed after completion of growth in order to achieve stable occlusion through either orthognathic surgery or camouflage orthodontic treatment. An eight-year-old patient visited the clinic exhibiting features of HFM with slight mandibular involvement. He received phase I treatment with distraction osteogenesis and a functional appliance. Distraction osteogenesis was performed at the right ramus, which resulted in an open bite at the right posterior dentition. After distraction osteogenesis, a functional appliance and partial fixed appliance were used to achieve extrusion of the affected posterior dentition and settlement of the occlusion adjustment on the unaffected posterior dentition. The patient visited the clinic regularly for follow-up assessments, and at the age of 20 years, he showed facial asymmetry of the mandible, which had deviated to the right side. He received orthodontic treatment to improve the occlusion of his posterior dentition after the growth period. Without orthognathic surgery, stable occlusion and a satisfactory facial appearance were obtained through camouflage orthodontic treatment.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제26권1호
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• pp.109-113
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• 2000

Synovial chondromatosis is an uncommon disease of cartilage transformation of synovial membrane with formation of loose bodies within the joint space. The knee and elbow are the most commonly involved sites and involvement of temporomandibular joint is very rare. Symtoms include swelling, pain, stiffness of the jaw, and inability to close the jaw. A case involving the temporomandibular joint(TMJ) is presented. A 28-year-old women had experienced pain of the left TMJ area and limitation of mouth opening. Radiographs of the left TMJ revealed calcified mass surrounding over the mandibular condyle and under the glenoid fossa. Treatment consisted of removal of calcified mass, reshaping of affected condyle and reconstruction with a auricular cartilage. After surgery, the patient's range of motion improved although deviation to the affected side. Until present after surgery there have been no recurrence of symtoms. We think that findings of this patitent agree with those of synovial synchondrmatosis in many aspects.

• 구강회복응용과학지
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• 제23권4호
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• pp.303-312
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• 2007

Recently several studies have been developed not only to apply bone materials to bony defect, but also to use osteogenic and osteoinductive materials to form bone more effectively. In 1998 Mark et al applied gel formation of PRP(platelet-rich plasma) in bony transplantation for mandibular reconstruction as one of the method of stimulating bone formation in maxillofacial area, which is contain of varies growth factors. After he reported that PRP accelerate bone formation, which is used in varies bone transplantation and augmentation with a good result. Especially there are amount of growth factors in PRP, and PRP increase angiogenesis, cell division, and mesenchymal cell growth. Moreover it is capable of osteoconduction, hemostatitis, anti-infection, forming the shape at transplantation, ease of handling, and recipient site stability. So it is known that success rate is high in bone transplantation. However PRP need tissue adhesive to make plasma to solid form. Thrombin and calcium chloride, component of PRP, is extracted from autogenic donor. So it is expensive to extract and there is possibility of hepatitis, AIDS, and hematogenous metastasis. After all, tissue adhesive have the limitation and danger of use. So we are willing to introduce that we had get some idea after using PRF(platelet-rich fibrin) in the various hard and soft tissue bony defect, which is self extracted simply and contain growth factors.

• 대한치과의사협회지
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• 제52권12호
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• pp.762-770
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• 2014

Bony exostosis, one of the osseous deformities, could act as a contributing factor of periodontal disease since it makes proper tooth brushing difficult and causes traumatic ulcer. The purpose of this case report is to show improvement of periodontal health by removal of bony exostoses and creation of physiologic osseous form. A 58 year-old female patient with recurrent ulcer and pain on bony exostoses located on left maxillary palatal area and both mandibular buccal areas was treated. Exostoses were removed and physiologically positive osseous form was created following vertical grooving, radicular blending, flattening interproximal bone and gradualizing marginal bone. The patient showed no further recurring traumatic ulcer and bone exposure. Moreover, periodontal pocket was eliminated and food impaction was decreased. In conclusion, periodontal health could be achieved through removal of multiple bony exostoses and development of ideal osseous form.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권2호
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• pp.131-136
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• 2016

Background: This study aimed to evaluate the patient's pain and quality of life after suture removal at either 3 or 7 days following the bilateral surgical extraction of impacted lower third molars. Methods: This study was a prospective, randomized controlled clinical trial carried out in 30 patients, who acted as their own control. Each patient required the bilaterally impacted mandibular third molars to be extracted. The impacted teeth were removed and the wound margins were approximated and sutured with black braided silk. The suture material was removed on day 3 on one side and on day 7 on the other. Each participant was asked to complete a questionnaire after the removal of the suture material on each designated day. Results: Regarding overall clinical symptoms, the mean VAS scores of male and female participants on day 3 were not significantly different from those on day 7. A significant difference was found in female participants, in that overall daily activity was better on day 7. There were significant differences in the ability to smile and laugh in both sexes and the ability to chew in the male participants was better on day 7. Conclusions: There were no significant differences in the patient's pain and quality of life between suture removal on day 3 or on day 7 following surgery to remove impacted lower third molars.

• 대한치과교정학회지
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• 제46권3호
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• pp.137-145
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• 2016

Objective: The purpose of this study was to investigate the characteristics of orthodontic patients at Yonsei Dental Hospital from 2008 to 2012. Methods: We evaluated Angle's classification from molar relationships, classification of skeletal malocclusion from the A point-nasion-B point angle, facial asymmetry, and temporomandibular joint disorders (TMDs) from the records of 7,476 patients who received an orthodontic diagnosis. The orthognathic surgery rate, extraction rate, and extraction sites were determined from the records of 4,861 treated patients. Results: The patient number increased until 2010 and gradually decreased thereafter. Most patients were aged 19-39 years, with a gradual increase in patients aged ${\geq}40years$. Angle's Class I, Class II divisions 1 and 2, and Class III malocclusions were observed in 27.7%, 25.6%, 10.6%, and 36.1% patients, respectively, with a gradual decrease in the frequency of Class I malocclusion. The proportion of patients with skeletal Class I, Class II, and Class III malocclusions was 34.3%, 34.3%, and 31.4%, respectively, while the prevalence of facial asymmetry and TMDs was 11.0% and 24.9%, respectively. The orthognathic surgery rate was 18.5%, with 70% surgical patients exhibiting skeletal Class III malocclusion. The overall extraction rate among nonsurgical patients was 35.4%, and the maxillary and mandibular first premolars were the most commonly extracted teeth. Conclusions: The most noticeable changes over time included a decrease in the patient number after 2010, an increase in the average patient age, and a decrease in the frequency of Angle's Class I malocclusion. Our results suggest that periodic characterization is necessary to meet the changing demands of orthodontic patients.