• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.1
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• pp.21-28
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• 2019

Objectives: Osteoradionecrosis (ORN) is one of the most severe complications resulting from radiotherapy (RT) in patients with head and neck cancer (HNC). It is characterized by persistent exposed and devitalized bone without proper healing for greater than 6 months after a high dose of radiation in the area. To describe the profile and dental management of ORN in HNC patients undergoing RT in an oncological clinical research center. Materials and Methods: A retrospective descriptive study was performed to analyze dental records from HNC patients with ORN treated at an oncological clinical research center from 2013 to 2017. A total of 158 dental records for HNC patients were selected from a total of 583 records. Afterwards, this number was distributed to three examiners for manual assessments. Each examiner was responsible for selecting dental records that contained an ORN description, resulting in 20 dental records. Results: Mean patient age was 60.3 years with males being the most affected sex (80.0%). The most affected area was the posterior region of the mandible (60.0%) followed by the anterior region of the mandible (20.0%) and the posterior region of the maxilla (10.0%). The factors most associated with ORN were dental conditions (70.0%) followed by isolated systemic factors (10.0%) and tumor resection (5.0%). There was total exposed bone closure in 50.0% of cases. The predominant treatment was curettage associated with chlorhexidine 0.12% irrigation (36.0%). Conclusion: Poor dental conditions were related to ORN occurrence. ORN management through less invasive therapies was effective for the closure of exposed bone areas and avoidance of infection.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.811-817
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• 2019

Radiation-therapy causes the adverse radiation effect. It is called osteoradionecrosis. A protein-therapy is carried out in order to cure osteoradionecrosis. The typical method of the protein-therapy is using BMP-2. Considering to bone damage, it is more important that maintains enough to circumstance regeneration for osteoblast differentiation on damage site of bone. Thus, this study is on a tissue regeneration to cure radiation critical damage. I observed that the formation of new regeneration bone by injection of collagen sheet BMP-2 on irradiated mouse. Consequently, I examined new bone formation with collagen sheet BMP-2 on irradiated mouse after 8weeks. Therefore I suggested that using collagen sheet BMP-2 which can be good for new bone regeneration effect on radiation side effect area.

• Imaging Science in Dentistry
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• v.51 no.1
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• pp.73-80
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• 2021

Purpose: The purpose of this study was to evaluate the cone-beam computed tomographic (CBCT) imaging and histopathological characteristics of osteoradionecrosis(ORN) and medication-related osteonecrosis of the jaw(MRONJ). Materials and Methods: Ten surgical specimens from segmental mandibulectomy (3 ORN and 7 MRONJ) were analyzed using CBCT. The CBCT parameters were as follows: high-resolution mode (tube voltage, 90.0 kV; tube current, 4.00 mA; rotation time, 16.8 s; field of view, 56 mm×56 mm; thickness, 0.099 mm). Histopathological characteristics were evaluated using histological slides of the surgical specimens. The Pearson chi-square test was used to compare ORN and MRONJ in terms of CBCT findings(internal texture, sequestrum, periosteal reaction and cortical perforation) and histopathological characteristics(necrotic bone, inflammatory cells, reactive bone formation, bacteria, Actinomyces, and osteoclasts). A P value less than 0.05 was considered to indicate statistical significance. Results: MRONJ showed periosteal reaction on CBCT more frequently than ORN (7 of 7 [100%] vs. 0 of 3 [0%], P<0.05). Regarding histopathological characteristics, MRONJ showed osteoclasts more frequently than ORN (6 of 7 [85.7%] vs. 0 of 3 [0%], P<0.05). Conclusion: This study evaluated the CBCT imaging and histopathological characteristics of ORN and MRONJ, and the findings suggest that CBCT could be useful for the evaluation of ORN and MRONJ.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.6
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• pp.440-441
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• 2020

• Maxillofacial Plastic and Reconstructive Surgery
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• v.19 no.2
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• pp.143-148
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• 1997

Cancer therapy for the head and neck malignoncy by surgery, radiotherapy, or combined modalities may cause substantial aesthetic and functional problems for the patient. The placement of osseointegrated implants into irradiated bone should only be performed when the predictability of achieving and maintaining osseointegration is high and the risk of developing of osteoradionecrosis is low. There are many benefits that irradiated patients may gain from the use of implants. A successful implant-retained prosthesis is dependent upon the implants attaining osseointegraton and then sustaining it during functional loads. The use of implants in irradiated patients requires high implant success rates that are acceptable to warrant their use. We report a case and review the literatures about implants in irradiated bone. In that case, the patient were undergone tumor resection and inner-table mandiblectomy due to squamous cell carcinoma of lower posterior gingiva. But 5 year later, the tumor were recurred, we resected the tumor and applied the radiation therapy. After then, we installed four IMZ implants after hyperbaric oxygenation, and made prosthesis using those implants. Until now they don't have any complications.

• The Korean Journal of Nuclear Medicine
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• v.24 no.2
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• pp.307-316
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• 1990

Irradiation is widely used for the treatment of malignant diseases, and possibly cause the osteoporosis. The densitometry and bone scintigraphy are valuable when used to monitor the patients longitudinally to access the progression of osteoporosis and risk of osteoradionecrosis. To evaluate the osteoporosis after irradiation of Cobalt-60 gamma ray on the lumbar spines of New Zealand white rabbits, bone densitometry by dual photon absorptiometry and bone scintigraphy were performed weekly. The decrease of bone density began at the first week after irradiation, and were in the nadir at 4-6th week. The osteoblastic activity measured by bone scintigraphy decreased in the first week, and was in the nadir at 4-6th week. The severity of these changes were related to the radiation dose. In conclusion, the osteoporosis before the presentation of the osteoradionecrosis can be diagnosed early with the dual photon absorptionmetry and bone scintigraphy.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.42
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• pp.28.1-28.4
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• 2020

Background: This clinical case presented a novel method of segmental mandible reconstruction using 3D-printed titanium implant with pre-mounted dental implants that was planned to rehabilitate occlusion. Case presentation: A 53-year-old male who suffered osteoradionecrosis due to the radiation after squamous cell carcinoma resection. The 3D-printed titanium implant with pre-mounted dental implant fixtures was simulated and fabricated with selective laser melting method. The implant was successfully inserted, and the discontinuous mandible defect was rehabilitated without postoperative infection or foreign body reaction during follow-ups, until a year. Conclusions: The 3D-printed titanium implant would be the one of the suitable treatment modalities for mandible reconstruction considering all the aspect of mandibular functions.

• Archives of Plastic Surgery
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• v.35 no.4
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• pp.439-445
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• 2008

Purpose: Malignant fibrous histiocytoma(MFH) is the most common soft tissue sarcoma in adult. As to this date, tissue development, treatment and prognosis of the tumor has not been definitely clarified, however, it has been reported that wide surgical resection of the tumor along with the radiotheraphy and chemotheraphy is needed for treatment. In MFH with high recurrence rate, the reconstruction method and points to be considered for reconstruction in recurrent case were studied in 10 patients who were treated in our hospital. Methods: From August of 1991 to August 2007, location of tumor, initial mass size, 1st recurred period, lymph node metastasis, recurrence rate, treatment modality, complication, reconstruction in recurrent defect, and follow up period was studied in 10 patients who underwent reconstruction at our Plastic surgery department following wide excision. Results: The average age was 62.8(46 - 73) years old, average follow up period was 7.7(1 - 17) years. Various reconstructions has been performed for recurrent cases and postoperative chemotheraphy and radiotheraphy was done. As for reconstruction in recurrent cases, After wide excision, local flap was performed in 6 cases, and free flap in 2 cases. After radiotherapy, osteoradionecrosis was occurred in 4 cases. Recurrence rate was 1 - 5(2.6) times and reconstruction due to recurrence was 7 out of 10 cases(70%). Conclusion: The treatment modality of MFH is not yet defined. Due to it's high recurrence rate, radiotherapy and chemotherapy is commonly combined with surgery. Even still, additional excision and reconstruction may be required. Therefore, possibility of re-operation must be considered when performing every excision and reconstruction; in case a recurrence or osteoradionecrosis occurs. Free flap coverage should be left as the last resort, according to the principle of reconstruction. Nevertheless, if the defect is large or osteoradionecrosis is present, it will benefit greatly to the patient's quality of life.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.4
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• pp.240-249
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• 2020

Objectives: Although the side effects of radiation therapy vary from mucositis to osteomyelitis depending on the dose of radiation therapy, to date, an experimental animal model has not yet been proposed. The aim of this study was to develop an animal model for assessing complications of irradiated bone, especially to quantify the dose of radiation needed to develop a rat model. Materials and Methods: Sixteen Sprague-Dawley rats aged seven weeks with a mean weight of 267.59 g were used. Atraumatic extraction of a right mandibular first molar was performed. At one week after the extraction, the rats were randomized into four groups and received a single dose of external radiation administered to the right lower jaw at a level of 14, 16, 18, or 20 Gy, respectively. Clinical alopecia with body weight changes were compared and bony volumetric analysis with micro-computed tomography (CT), histologic analysis with H&E were performed. Results: The progression of the skin alopecia was different depending on the irradiation dose. Micro-CT parameters including bone volume, bone volume/tissue volume, bone mineral density, and trabecular spaces, showed no significant differences. The progression of osteoradionecrosis (ORN) along with that of inflammation, fibrosis, and bone resorption, was found with increased osteoclast or fibrosis in the radiated group. As the radiation dose increases, osteoclast numbers begin to decrease and osteoclast tends to increase. Osteoclasts respond more sensitively to the radiation dose, and osteoblasts are degraded at doses above 18 Gy. Conclusion: A standardized animal model clinically comparable to ORN of the jaw is a valuable tool that can be used to examine the pathophysiology of the disease and trial any potential treatment modalities. We present a methodology for the use of an experimental rat model that incorporates a guideline regarding radiation dose.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.46 no.6
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• pp.443-444
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• 2020