• 대한치과의사협회지
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• 제55권8호
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• pp.556-564
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• 2017

Endodontic surgery is a procedure to treat apical periodontitis or abscess in cases that did not heal after nonsurgical treatment or retreatment. This might include situations with persistent intracanal infection after root canal treatment. Other reasons might be found in extraradicular infection, such as bacterial biofilm on the apical root surface or bacteria within the lesion. For many years, the treatment standard was the traditional approach with surgical burs and amalgam for root-end filling. Endodontic microsurgery is the most recent step in the evolution of endodontic surgery, applying not only ultrasonic tip and biocompatible filling materials but also incorporating high-power magnification and illumination. Although many studies have been published that advocate the use of modern technique, the traditional techniques are still widely used in the surgery community. The purpose of this study was to demonstrate the endodontic microsurgery procedure including the root-end preparation and filling with the use of a surgical operating microscope.

• Restorative Dentistry and Endodontics
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• 제44권3호
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• pp.30.1-30.6
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• 2019

We report the surgical endodontic treatment of a maxillary first premolar with a lateral lesion that originated from an accessory canal. Although lesions originating from accessory canals frequently heal with simple conventional endodontic therapy, some lesions may need additional and different treatment. In the present case, conventional root canal retreatment led to incomplete healing with the need for further treatment (i.e., surgery). Surgical endodontic management with a fast-setting calcium silicate cement was performed on the accessory canal using a dental operating microscope. At the patient's 9-month recall visit, the lesion was resolved upon radiography.

• Restorative Dentistry and Endodontics
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• 제47권2호
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• pp.17.1-17.8
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• 2022

Endodontic microsurgery is a predictable treatment option when orthograde treatment or retreatment is unsuccessful or unfeasible. However, when there is a gross compromise of periapical bone, achievement of bone regeneration after the surgical procedure may be hampered. In such cases, the application of guided tissue regeneration principles, with adjunctive use of leukocyte platelet-rich fibrin to fill the bone defect as a bone substitute and as a membrane to cover the site, provides a cost-effective solution with the benefits of accelerated physiological healing and reduced post-surgical pain and discomfort. This case report presents 2 cases of endodontic microsurgery of the upper lateral incisors with loss of buccal cortical plate, where platelet-rich fibrin was successfully applied.

• Restorative Dentistry and Endodontics
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• 제36권6호
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• pp.465-476
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• 2011

최근의 근관치료학 분야에서 외과적 재치료는 수술현미경, 초음파기구, 미세수술기구 등의 도입으로 많은 변화가 있어 왔다. 본 논문에서는 기존의 전통적인 치근단 수술법과 비교하여 미세 치근단 수술의 주요 술식을 알아보고 이미 출간된 논문에 근거하여 미세 치근단 수술의 성공과 실패 그리고 성공과 실패에 영향을 미치는 요소들을 고찰하고자 하였다. 수술현미경은 수술부위를 밝게 확대해서 봄으로써 치근단 부위의 미세한 형태를 조명할 수 있게 되었으며 이는 술식의 성공을 위해서 필수적인 요소가 되었다. 초음파 기구 또한 치근단 역충전을 위한 정확한 와동형성을 가능하게 해 주었다. 따라서 미세 치근단 수술은 기존방식의 문제점이었던 많은 골삭제, 경사진 치근절제, 부정확한 역충전 와동 형성, 치근단 미세구조 관찰의 어려움 등을 극복함으로써 술식이 더욱 정확해지고, 성공가능성이 더 높아졌다고 볼 수 있다. 미세 치근단 수술에 영향을 미치는 요소에는 다양한 요인들이 존재할 수 있으나 전통방식의 치근단 수술보다 술식이 표준화 됨으로써 술식에 의한 영향을 줄일 수 있다. 환자와 치아에 관계되는 요소 중에서는 치주질환의 이환 여부와 치아위치(tooth position)가 예후에 영향을 미치는 것으로 알려져 있으나 이에 대한 연구는 아직까지 그 수가 부족한 상태로 앞으로 검증수준 (evidence level)이 높은 Randomized clinical trial 혹은 전향적 코호트 연구가 많이 이루어져야 할 것이다.

• Journal of Korean Neurosurgical Society
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• 제37권3호
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• pp.179-186
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• 2005

Objective: The purpose of this paper is to report our experiences in managing seventeen cases of residual intracranial aneurysms following surgical or endovascular treatment and discuss the incidence of residual aneurysms, the indications and technique of retreatment of residual aneurysms. Methods: During a period of 42 months, we treated 391 aneurysms in 339 patients with microsurgical clipping or GDC embolization as a primary treatment. In 39 of them, follow-up angiography revealed residual aneurysms and seventeen of whom were retreated. There were eleven cases in ACoA, three cases in distal ICA, one, in each of MCA, ACA and basilar artery. We reviewed retrospectively the clinical notes, operation records and cerebral angiograms of seventeen patients who had been treated for residual aneurysms. Results: Complementary treatment was performed in 8 cases by means of surgery and in 9 cases by means of GDC embolization. There were eleven females and six males with an age variation between 29 and 78 years. The mean duration of angiographic follow-up was 17.3 months. Of the seventeen cases that were treated for residual aneurysms, fourteen achieved complete occlusion. Of 17 retreated patients, fifteen patients had good recovery according to the Glasgow Outcome Scale. Conclusion: When occlusion after endovascular or surgical treatment is incomplete, a new multidisciplinary approach should be carried out. Given our experiences, we recommend coil embolization of the choice in cases that the residual aneurysmal neck had been narrowed by previous clipping. On the other hand, if the residual aneurysm has enough space to clip but not enough to coil, we recommend the microsurgical clipping.

• Restorative Dentistry and Endodontics
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• 제46권4호
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• pp.49.1-49.8
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• 2021

Objectives: To evaluate the fracture incidence of Reciproc R25 instruments (VDW) used during non-surgical root canal retreatments performed by students in a postgraduate endodontic program. Materials and Methods: From the analysis of clinical record cards and periapical radiographs of root canal retreatments performed by postgraduate students using the Reciproc R25, a total of 1,016 teeth (2,544 root canals) were selected. The instruments were discarded after a single use. The general incidence of instrument fractures and its frequency was analyzed considering the group of teeth and the root thirds where the fractures occurred. Statistical analysis was performed using the χ² test (p < 0.01). Results: Seven instruments were separated during the procedures. The percentage of fracture in relation to the number of instrumented canals was 0.27% and 0.68% in relation to the number of instrumented teeth. Four fractures occurred in maxillary molars, 1 in a mandibular molar, 1 in a mandibular premolar and 1 in a maxillary incisor. A greater number of fractures was observed in molars when compared with the number of fractures observed in the other dental groups (p < 0.01). Considering all of the instrument fractures, 71.43% were located in the apical third and 28.57% in the middle third (p < 0.01). One instrument fragment was removed, one bypassed, while in 5 cases, the instrument fragment remained inside the root canal. Conclusions: The use of Reciproc R25 instruments in root canal retreatments carried out by postgraduate students was associated with a low incidence of fractures.

• Restorative Dentistry and Endodontics
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• 제39권2호
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• pp.137-142
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• 2014

This article presents the successful surgical management of a failed mineral trioxide aggregate (MTA) orthograde obturation of a tooth with a history of impact trauma and perforated internal root resorption. A symptomatic maxillary lateral incisor with a history of perforation due to internal root resorption and nonsurgical repair using MTA was referred. Unintentional overfill of the defect with MTA had occurred 4 yr before the initial visit. The excess MTA had since disappeared, and a radiolucent lesion adjacent to the perforation site was evident radiographically. Surgical endodontic retreatment was performed using calcium enriched mixture (CEM) cement as a repair material. Histological examination of the lesion revealed granulation tissue with chronic inflammation, and small fragments of MTA encapsulated within fibroconnective tissue. At the one and two year follow up exams, all signs and symptoms of disease had resolved and the tooth was functional. Complete radiographic healing of the lesion was observed two years after the initial visit. This case report illustrates how the selection of an appropriate approach to treatment of a perforation can affect the long term prognosis of a tooth. In addition, extrusion of MTA into a periradicular lesion should be avoided.

• Restorative Dentistry and Endodontics
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• 제43권2호
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• pp.16.1-16.9
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• 2018

Objectives: Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods: This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results: Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions: Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment.

• Radiation Oncology Journal
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• 제35권1호
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• pp.1-15
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• 2017

Locoregional failure is the most frequent pattern of failure in locally advanced head and neck cancer patients and it leads to death in most of the patients. Second primary tumors occurring in the other head and neck region reach up to almost 40% of long-term survivors. Recommended and preferred retreatment option in operable patients is salvage surgical resection, reporting a 5-year overall survival of up to 40%. However, because of tumor location, extent, and underlying comorbidities, salvage surgery is often limited and compromised by incomplete resection. Reirradiation with or without combined chemotherapy is an appropriate option for unresectable recurrence. Reirradiation is carefully considered with a case-by-case basis. Reirradiation protocol enrollment is highly encouraged prior to committing patient to an aggressive therapy. Radiation doses greater than 60 Gy are usually recommended for successful salvage. Despite recent technical improvement in intensity-modulated radiotherapy (IMRT), the use of concurrent chemotherapy, and the emergence of molecularly targeted agents, careful patient selection remain as the most paramount factor in reirradiation. Tumors that recur or persist despite aggressive prior chemoradiation therapy imply the presence of chemoradio-resistant clonogens. Treatment protocols that combine novel targeted radiosensitizing agents with conformal high precision radiation are required to overcome the resistance while minimizing toxicity. Recent large number of data showed that IMRT may provide better locoregional control with acceptable acute or chronic morbidities. However, additional prospective studies are required before a definitive conclusion can be drawn on safety and effectiveness of IMRT.

• Journal of Korean Neurosurgical Society
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• 제65권5호
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• pp.633-639
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• 2022

Accurate diagnosis of trigeminal neuralgia (TN) is the starting point for optimal treatment. Gamma knife radiosurgery (GKRS) is currently regarded as one of the first-line treatment options for medically refractory TN. GKRS is a less invasive treatment with a low risk of complications than other surgical procedures that provides a favorable pain control Barrow Neurological Institute (BNI) I-IIIb rate of >75% at short-term follow-up. Drawbacks of GKRS include the latency period before pain relief and higher recurrence rate compared with microvascular decompression. Therefore, repeat treatment is necessary if the initial GKRS was effective but followed by recurrence. The concept of dose rate and the biologically effective dose of radiation has been actively studied in radiation oncology and is also applied in GKRS for TN to achieve high safety and efficacy by prescribing the optimal dose. Recent progress in functional imaging, such as diffusion tensor imaging, enables us to understand the pathophysiology of TN and predict the clinical outcome after GKRS. Here, we review TN, GKRS, and recent updates, especially in the concepts of radiation dose, diffusion tensor imaging studies, and repeat treatment in GKRS for TN.