• 대한치과교정학회지
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• 제46권6호
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• pp.395-408
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• 2016

We report a case involving a young female patient with severe mandibular retrognathism accompanied by mandibular condylar deformity that was effectively treated with Le Fort I osteotomy and two genioplasty procedures. At 9 years and 9 months of age, she was diagnosed with Angle Class III malocclusion, a skeletal Class II jaw relationship, an anterior crossbite, congenital absence of some teeth, and a left-sided cleft lip and palate. Although the anterior crossbite and narrow maxillary arch were corrected by interceptive orthodontic treatment, severe mandibular hypogrowth resulted in unexpectedly severe mandibular retrognathism after growth completion. Moreover, bilateral condylar deformities were observed, and we suspected progressive condylar resorption (PCR). There was a high risk of further condylar resorption with mandibular advancement surgery; therefore, Le Fort I osteotomy with two genioplasty procedures was performed to achieve counterclockwise rotation of the mandible and avoid ingravescence of the condylar deformities. The total duration of active treatment was 42 months. The maxilla was impacted by 7.0 mm and 5.0 mm in the incisor and molar regions, respectively, while the pogonion was advanced by 18.0 mm. This significantly resolved both skeletal disharmony and malocclusion. Furthermore, the hyoid bone was advanced, the pharyngeal airway space was increased, and the morphology of the mandibular condyle was maintained. At the 30-month follow-up examination, the patient exhibited a satisfactory facial profile. The findings from our case suggest that severe mandibular retrognathism with condylar deformities can be effectively treated without surgical mandibular advancement, thus decreasing the risk of PCR.

• The Journal of Advanced Prosthodontics
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• 제10권4호
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• pp.265-270
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• 2018

PURPOSE. The purpose of this in vitro study was to evaluate the accuracy of a new implant impression technique using bite impression coping and a dual arch tray. MATERIALS AND METHODS. Two implant fixtures were placed on maxillary left second premolar and first molar area in dentoform model. The model with two fixtures was used as the reference. The impression was divided into 2 groups, n=10 each. In group 1, heavy/light body silicone impression was made with pick up impression copings and open tray. In group 2, putty/light body silicone impression was made with bite impression copings and dual arch tray. The reference model and the master casts with implant scan bodies were scanned by a laboratory scanner. Surface tessellation language (STL) datasets from test groups was superimposed with STL dataset of reference model using inspection software. The three-dimensional deviation between the reference model and impression models was calculated and illustrated as a color-map. Data was analyzed by independent samples T-test of variance at ${\alpha}=.05$. RESULTS. The mean 3D implant deviations of pick up impression group (group 1) and dual arch impression group (group 2) were 0.029 mm and 0.034 mm, respectively. The difference in 3D deviations between groups 1 and 2 was not statistically significant (P=.075). CONCLUSION. Within limitations of this study, the accuracy of implant impression using a bite impression coping and dual arch tray is comparable to that of conventional pick-up impression.

• 대한장애인치과학회지
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• 제14권1호
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• pp.26-30
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• 2018

9세 레녹스-가스토 증후군을 앓고 있는 여아가 정기검진을 위해 연세대학교 치과대학병원 소아치과에 내원하였으며 구강 내 임상 검사 시 유견치 및 제1유구치의 동요도가 관찰되었다. 본과 내원 두 달 전 폐렴으로 인한 입원 및 치아로 추정되는 물질의 흡인 병력이 있었으며 치과에 내원했을 당시 구강 내에서 상악 좌측 제1유구치가 관찰되지 않았다. 해당 치아가 흡인되어 폐렴을 유발했을 가능성이 높은 것으로 판단하고 동요도가 있는 나머지 유치의 발치를 시행하였다. 인후 반사가 제한되어 흡인 위험성이 높은 장애 환자들에서는 치과 치료 상황 외에도 구강 내 이물질의 흡인이 일어날 수 있으므로 동요도가 있는 유치나 잘 맞지 않는 보철물 등을 예방적으로 제거하는 것이 흡인의 위험성을 줄일 수 있을 것으로 생각된다.

• 대한장애인치과학회지
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• 제14권1호
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• pp.31-35
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• 2018

부산대학교 치과병원 소아치과에 내원한 Shell teeth에 이환된 소아 환자를 전신마취 하에 치료하였다. 임상검사시 다수 치아의 치관 파괴와 치수 노출 및 상악 유전치 잔존치근이 관찰되었다. 방사선검사상 전반적인 유치열에서 정상보다 큰 크기의 치수강과 넓은 치근관 및 얇은 경조직 층이 존재했으며 발생중인 영구치 치배의 형태이상이 관찰되었다. 환자의 언니와 아버지를 포함한 부계 가족 구성원 일부에서 상아질형성부전증 병력이 조사되었다. 치료시 수복이 불가능한 치아는 발거하였고 보존 가능한 치아는 치수치료 및 기성금속관, 복합레진 수복치료를 시행하였다. 치료 결과 환자의 통증이 감소하였고 저작능력이 회복되었다. 주기적인 내원 및 경과관찰이 요구된다.

• 대한치과기공학회지
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• 제34권4호
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• pp.353-359
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• 2012

Purpose: The aim of this study measured and compared the marginal and internal fit of metal cores with two base metal alloy (Ni-Cr alloy(non-beryllium), Co-Cr alloy). Methods: Maxillary right first molar abutment fabricated by titanium was prepared for this study. Impressions(10ea) were made from titanium model, and study models were poured with improved dental stone. Wax cores of twenty were prepared for burn-out and casting. Ten wax cores cast Ni-Cr alloy(non-Be), and finally ten cast Co-Cr alloy. Marginal and internal fit of cores was evaluated using silicone replica technique and digital microscope(x160). The data were statistically analyzed with the independent samples t-test (${\alpha}$ <.05). Results: Mean(standard deviation, SD) marginal and internal fit total size of Ni-Cr alloy(non-Be) group was $73.3(14.4){\mu}m$ and of Co-Cr alloy group $65.6(17.4){\mu}m$. The marginal and internal fit total size of Ni-Cr alloy group(non-Be) was statistically significantly greater than that of Co-Cr alloy group (P=.004). Conclusion: Co-Cr alloy cores in this study had a better marginal fit than Ni-Cr alloy(non-Be) cores.

• Journal of Periodontal and Implant Science
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• 제26권1호
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• pp.293-308
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• 1996

Recently, dental laser have been applied for removal of soft tissues, hemostasis and blood coagulation, removal of benign and malignant tumor, treatment of leukoplakia, aphthous ulcer and herpetic lesion, implant second surgery, removal of granulation tissue, frenectomy, clinical crown lengthening, gingivectomy, gingivoplasty, and treatment of dentin hypersensitivity. Even though the frequency of laser treatment is increasing, the research on the healing process after gingivectomy using pulsed Nd : YAG laser is very rare. The purpose of this study was to observe and compare the wound healing after gingivectomy using scalpel and pulsed Nd : YAG laser in the rat. Gingivectomy was performed using pulsed Nd : YAG laser(SUNRISE Technologies, U.S.A., 1.5 Watts, 10 pps) on the buccal gingiva of right maxillary first molar and using scalpel(No.12) on the contralateral side. Those sites treated by surgical scalpel were designated as the control, and by pulsed Nd : YAG laser as the experimental group. Animals were sacrificed at 1, 2, 3, 5, 7, 11 and 14 days postoperatively, and specimens were histologically observed under light microscope. The results were as follows : 1. Clinical observation Normal color and shape were observed at the 5th day ill the control group and the 7th day in the experimental group. 2. Histologic findings 1) In the control group, denser inflammatory infiltration was observed. 2) Epithelialization started at the 2nd day in the control group, similar to the experimental group, and completed at the 11th to the 14th day postoperatively. 3) In the experimental group, connective tissue showed the vacuole formation and degenerative change during early healing period. Healing of connective tissue was slower in the experimental group than in the control group by 2 days. 4) In the both groups, wound healing was completed at the 2nd week. From this study, gingivectomy using pulsed Nd : YAG laser seems to result in a little delayed wound healing process, compared to the gingivectomy using scalpel. Considering the clinical advantages of laser surgery, pulsed Nd : YAG laser might be useful device for gingivectomy.

• The Journal of Advanced Prosthodontics
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• 제7권4호
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• pp.294-302
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• 2015

PURPOSE. The purpose of this study was to verify the clinical-feasibility of additive manufacturing by comparing the accuracy of four different manufacturing methods for metal coping: the conventional lost wax technique (CLWT); subtractive methods with wax blank milling (WBM); and two additive methods, multi jet modeling (MJM), and micro-stereolithography (Micro-SLA). MATERIALS AND METHODS. Thirty study models were created using an acrylic model with the maxillary upper right canine, first premolar, and first molar teeth. Based on the scan files from a non-contact blue light scanner (Identica; Medit Co. Ltd., Seoul, Korea), thirty cores were produced using the WBM, MJM, and Micro-SLA methods, respectively, and another thirty frameworks were produced using the CLWT method. To measure the marginal and internal gap, the silicone replica method was adopted, and the silicone images obtained were evaluated using a digital microscope (KH-7700; Hirox, Tokyo, Japan) at 140X magnification. Analyses were performed using two-way analysis of variance (ANOVA) and Tukey post hoc test (${\alpha}=.05$). RESULTS. The mean marginal gaps and internal gaps showed significant differences according to tooth type (P<.001 and P<.001, respectively) and manufacturing method (P<.037 and P<.001, respectively). Micro-SLA did not show any significant difference from CLWT regarding mean marginal gap compared to the WBM and MJM methods. CONCLUSION. The mean values of gaps resulting from the four different manufacturing methods were within a clinically allowable range, and, thus, the clinical use of additive manufacturing methods is acceptable as an alternative to the traditional lost wax-technique and subtractive manufacturing.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제14권4호
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• pp.275-282
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• 1992

Maxillofacial war injures is specific representative of severe hard and soft tissue defect. This type of injuries were different from the trauma because it may be fatal. The purpose of this study was to evaluate the injury type base on the retrograde medical record in the 104 patients from Feb. 1991 to Aug. 1992 in Korea Veterans Hospital. The obtained results were as follows. 1. Among 104 cases, 51 cases(49.0%) were classified as mandibular defects only, and 53 cases (51.0%) were classified as maxillary with mandibular defect (combined). 2. The etiologic factors of injury were gunshot, artillery and grenade or shell: 33 cases, 14cases, and 10 cases respectively in Korea War, 19 cases, 5 cases, and 8 cases respectively in Vietnam War. 3. In 57 cases of mandibular partial defect, the angle area showed the highest frequencies, 18 cases(31.6%). 4. In 42 cases of mandibular segmental defect, the area between the 1st molar and the ascending ramus showed the highest frequencies. 17 cases(40.4%), and almost all cases were unilateral defect (40 cases, 95.0%) 5. Reconstruction method performed for segmental mandibular defect were wire or plate(15 cases, 35.7%) and soft tissue closure only(12 cases, 28.7%), respectively.

• 대한치과교정학회지
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• 제23권2호
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• pp.165-177
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• 1993

Upper canine is important because it protects and maintains the stability of the dental arch and also, joins the anterior with the posterior teeth. The incidence of impaction of upper canine is the second most frequent next to the third molar because it takes a long period of time to develop, and has a complicated path of eruption, and erupts lately. After the age of 10, clinical and radioglaphic examination can be used in revealing the possibility of impaction and efforts should be put to reduce the side effects. To prevent impaction, selective extraction of primary canine at the age of 8 to 9 could be considered and prolonged retention of primary canine in oral cavity should be avoided at this time. Once the impaction is iden, the first stage of the treatment is to lcocalize the lesion by radiographic examination and According to the severity, orthodontic traction or autotransplantation should be considered and comprehensive diagnosis and treatment plan of malocclusion should be established. Generally, labial impaction is due to arch length discrepancy and palatal impaction is due to malposition or morphologic pathosis of lateral incisors rather than arch length discrepancy. In surgical procedure, peridontal problems should be considered and the minimum amount of bone and soft tissue should be reduced and direct bonding method of many attachment methods should be recommended. Especially in traction of labially impacted canine, it should be guided to erupt through the keratinized zone and proper forced magnitude should be applied. The importance of periodontal condition should always be in mind following the patient education to mintain the good oral hygiene at each stage of treatment. Properly managed impacted canine can provide function and esthetic by proper diagnosis and treatment if extraction of canine is not indicated.

• 대한치과교정학회지
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• 제39권6호
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• pp.402-419
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• 2009

성장이 종료된 치성 또는 골격성 개방교합 환자를 치료하는 것은 매우 어려운 일이다. 전치부 개방교합 환자는 증가된 전안면고경, 상악 구치부의 과도한 수직성장, 큰 하악각 등의 특징을 지닌다. 이러한 증례에서 구치의 압하를 통한 개방교합의 해소는 좋은 치료전략이다. 본 연구는 교정용 미니임플란트를 이용하여 개방교합을 치료하고 성공적인 유지를 얻은 두 명의 환자에 대한 보고이다. 적절한 진단이 시행되고 교정용 미니임플란트 등의 장치를 이용한 치료기법을 적용하면 수술치료 없이 교정치료만으로 개방교합의 치료가 가능하며, 하악구치부에 posterior bite block을 추가한 가철식 유지장치 및 SFR이 개교환자를 위한 유지장치 또는 보조유지장치로 유용하게 사용될 수 있다는 결론을 얻었다.