Clinical significance of drug cessation on medication-related osteonecrosis of the jaw in patients with osteoporosis

Kezia Rachellea Mustakim(Kezia Rachellea Mustakim ),Mi Young Eo(Mi Young Eo),Ju Young Lee(Ju Young Lee),Mi Hyun Seo(Mi Hyun Seo),Soung Min Kim(Soung Min Kim) 대한구강악안면외과학회 2023 대한구강악안면외과학회지 Vol.49 No.2

Objectives: Suspending bisphosphonates (BPs) to reduce the risk and severity of medication-related osteonecrosis of the jaw (MRONJ) remains controversial. In this study, we quantitatively evaluated the clinical significance of BP suspension before surgery in osteoporosis patients with MRONJ. Materials and Methods: We analyzed 24 osteoporosis patients with MRONJ who were treated from 2012 to 2020 at Seoul National University Dental Hospital and compared the treatment outcomes of those who suspended BPs with those who did not. The number of surgical interventions, follow-up panoramic radiographs for relative bone density measurement, and laboratory blood tests including white blood cells, erythrocyte sedimentation rate, absolute neutrophil count, hemoglobin, hematocrit, and alkaline phosphatase were analyzed. ANOVA, Student’s t -test, and Mann–Whitney U tests were used to compare results. Fisher’s exact test was used to discover the association between treatment outcome and BP suspension, and Pearson’s correlation test was used to measure the statistical relationship between the changes in serum inflammatory markers. Results: The number of interventions was significantly higher in the non-drug suspension group due to recurrence (P<0.05). The relative bone density in patients who suspended BPs was significantly different over time (P<0.05), with the highest density at one-year follow-up. Fisher’s exact test shows an association between successful treatment outcomes and BP suspension. The alkaline phosphatase and erythrocyte sedimentation rate levels decreased significantly in the BP-suspended group, and a positive correlation was found between these elevated markers. Conclusion: A significant increase in bone density throughout follow-up and a lower number of interventions were found in the BP suspension group compared to the non-drug suspension group. Also, BP suspension decreased inflammatory markers in the serum after surgery, resulting in good treatment outcomes. BP suspension is a prognostic factor for MRONJ and should be implemented before surgery.

Guidance and rationale for the immediate implant placement in the maxillary molar

Kezia Rachellea Mustakim(Kezia Rachellea Mustakim ),Mi Young Eo(Mi Young Eo),Ju Young Lee(Ju Young Lee),Hoon Myoung(Hoon Myoung ),Mi Hyun Seo(Mi Hyun Seo),Soung Min Kim(Soung Min Kim) 대한구강악안면외과학회 2023 대한구강악안면외과학회지 Vol.49 No.1

Objectives: While the reliability of immediate implant placement in the maxillary molar has been discussed, its significance is questionable. There have been no guidelines for case selection and surgical technique for successful treatment outcomes of immediate maxillary molar implants. Therefore, in this study, we classified alveolar bone height and socket morphology of the maxillary molar to establish guidelines for immediate implant placement. Materials and Methods: From 2011 to 2019, we retrospectively analyzed 106 patients with 148 immediate implants at the Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital. Inclusion and exclusion criteria were applied, and patient characteristics and treatment results were evaluated clinically and radiologically. Results: A total of 29 tapered, sand-blasted, large-grit, and acid-etched (SLA) surfaces of implants were placed in 26 patients. The mean patient age was 64.88 years. Two implants failed and were reinstalled, resulting in a 93.10% survival rate. Fluctuating marginal bone level changes indicating bone regeneration and bone loss were observed in the first year following installation and remained stable after one year of prosthesis loading, with an average bone loss of 0.01±0.01 mm on the distal side and 0.03±0.03 mm on the mesial side. Conclusion: This clinical study demonstrated the significance of immediate implant placement in maxillary molars as a reliable treatment with a high survival rate using tapered SLA implants. With an accurate approach to immediate implantation, surgical intervention and treatment time can be reduced, resulting in patient satisfaction and comfort.

Development of a standardized mucositis and osteoradionecrosis animal model using external radiation

Mi Hyun Seo,Min Young Lee,Mi Young Eo,Suk Keun Lee,Kyung Mi Woo,Soung Min Kim 대한구강악안면외과학회 2020 대한구강악안면외과학회지 Vol.46 No.4

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.

F-70 Generation of lung cancer cell lines harboring EGFR T790M mutation using CRISPR/Cas9-mediated genome editing

( Mi-young Park ),( Min Hee Jung ),( Eun Young Eo ),( Seokjoong Kim ),( Sang Hoon Lee ),( Yeon Joo Lee ),( Jong Sun Park ),( Young Jae Cho ),( Jin Haeng Chung ),( Cheol Hyeon Kim ),( Ho Il Yoon ),( Ja 대한결핵 및 호흡기학회 2016 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.121 No.0

Tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib are effective against lung adenocarcinomas harboring epidermal growth factor receptor (EGFR) mutations. However, cancer cells can develop resistance to these agents with prolonged ex-posure; in over 50% of cases, this is attributable to the EGFR T790M mutation. Moreover, additional resistance mutations can arise with the use of new drugs. Cancer cell lines with specific mutations can enable the study of resistance mechanisms. In this study, we introduced the EGFR T790M mutation into the PC9 human lung cancer cell line which has a deletion in exon 19 of the EGFR gene by the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas)9-mediated genome editing. EGFR pyrosequencing revealed that PC9-EGFR T790M cell clones had a higher T790M muta-tion rate than PC9-G cells generated by long-term exposure to gefitinib; moreover, resistance in these clones was comparable to or higher than that in PC9-G cells. The clones were also highly sensitive to the 3rd-generation EGFR TKI (AZD9291), which is cytotoxic to lung cancer cells with EGFR T790M. The CRISPR/Cas9 programmable nuclease system can be used to generate various cancer cell lines with specific mutations that can facilitate studies on resistance mechanisms and drug efficacy.

Energy-dispersive X-ray spectroscopic investigation of a fractured non-submerged dental implant associated with abutment fracture

Truc Thi Hoang Nguyen(Truc Thi Hoang Nguyen ),Mi Young Eo(Mi Young Eo),Kezia Rachellea Mustakim(Kezia Rachellea Mustakim ),Mi Hyun Seo(Mi Hyun Seo),Hoon Myoung(Hoon Myoung ),Soung Min Kim(Soung Min Ki 대한구강악안면외과학회 2023 대한구강악안면외과학회지 Vol.49 No.1

The biocompatibility and durability of implant fixtures are major concerns for dentists and patients. Mechanical complications of the implant include abutment screw loosening, screw fracture, loss of implant prostheses, and implant fracture. This case report aims to describe management of a case of fixture damage that occurred after screw fracture in a tissue level, internal connection implant and microscopic evaluation of the fractured fixture. A trephine bur was used to remove the fixture, and the socket was grafted using allogeneic bone material. The failed implant was examined by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS), which revealed a fractured fixture with both normal and irregular bone patterns. The SEM and EDS results give an enlightenment of the failed fixture surface micromorphology with microfracture and contaminated chemical compositions. Noticeably, the significantly high level of gold (Au) on the implant surface and the trace amounts of Au and titanium (Ti) in the bone tissue were recorded, which might have resulted from instability and micro-movement of the implant-abutment connection over an extended period of time. Further study with larger number of patient and different types of implants is needed for further conclusion.

구강 및 안면재건을 위한 광배근 유리피판의 해부학적 고찰

김성민,정영언,어미영,강지영,서미현,김현수,명훈,이종호,Kim, Soung-Min,Jung, Young-Eun,Eo, Mi-Young,Kang, Ji-Young,Seo, Mi-Hyun,Kim, Hyun-Soo,Myoung, Hoon,Lee, Jong-Ho 대한악안면성형재건외과학회 2011 Maxillofacial Plastic Reconstructive Surgery Vol.33 No.6

The latissimus dorsi myocutaneous flap (LDMF) was initially described at the turn of the century by Tansini et al, and latissimus dorsi myocutaneous free flap (LDMFF) was also first described for the coverage of a chronically infected scalp by Maxwell et al. As a pedicled flap, LDMF has been often used for breast reconstruction and for soft tissue replacement near the shoulder and the lower reaches of the head and neck. LDMFF is a flat and broad soft tissue flap with large-caliber thoracodorsal vessels for microvascular anastomosis. A skin paddle of the LDMFF can be more than $20{\times}40$ cm, so very large defects in the oral cavity and outer facial region can be covered by this LDMFF. Other advantages include consistent vascular anatomy, acceptable donor site morbidity and the ability to perform simultaneous flap harvest with tumor resection. For a better understanding of LDMFF as a routine reconstructive procedure in large defects of the oral cavity and facial legion, anatomical findings must be learned and memorized by young doctors during the special curriculum periods for the Korean national board of oral and maxillofacial surgery. This review article discusses the anatomical basis of LDMFF with Korean language.

구강재건을 위한 요골전완 유리피판의 해부학적 고찰

김성민,서미현,강지영,어미영,명훈,이석근,이종호,Kim, Soung-Min,Seo, Mi-Hyun,Kang, Ji-Young,Eo, Mi-Young,Myoung, Hoon,Lee, Suk-Keun,Lee, Jong-Ho 대한악안면성형재건외과학회 2011 Maxillofacial Plastic Reconstructive Surgery Vol.33 No.1

Reconstruction following a resection of malignant oral cavity tumors is one of the most difficult problems in recent oral oncology. The radial forearm free flap (RFFF) is a thin, pliable soft tissue flap with large-caliber vessels for microvascular anastomosis. Its additional advantages include consistent flap vascular anatomy, acceptable donor site morbidity and the ability to perform simultaneous flap harvest with a tumor resection. For a better understanding of RFFF as a routine reconstructive procedure in oral and maxillofacial surgery, the constant anatomical findings must be learned and memorized by young doctors during the special curriculum periods for the Korean national board of oral and maxillofacial surgery. This review article discusses the anatomical basis of RFFF in the Korean language.

Reasonable necessity of preoperative laboratory tests in office-based oral and maxillofacial surgery

Mi Hyun Seo,Mi Young Eo,Kezia Rachellea Mustakim,Buyanbileg Sodnom-Ish,Hoon Myoung,Soung Min Kim 대한구강악안면외과학회 2023 대한구강악안면외과학회지 Vol.49 No.3

Objectives: As medical history before surgery is often based on patient reporting, there is the possibility that patients intentionally hide underlying diseases or that dentists cannot recognize abnormal health states. Therefore, more professional and reliable treatment processes are needed under the Korean dental specialist system. The purpose of this study was to elucidate the necessity of a preoperative blood testing routine prior to office-based surgery under local anesthesia. Patients and Methods: Preoperative blood lab data for 5,022 patients from January 2018 to December 2019 were assembled. Study participants were those who underwent extraction or implant surgery under local anesthesia at Seoul National University Dental Hospital. Preoperative blood tests included complete blood count (CBC), blood chemistry, serum electrolyte, serology, and blood coagulation data. Values outside of the normal range were considered an “abnormality,” and the percentage of abnormalities among the total number of patients was calculated. Patients were divided into two groups based on the presence of underlying disease. The rates of abnormalities in the blood tests were compared between groups. Chi-square tests were performed to compare data from the two groups, and P<0.05 was considered statistically significant. Results: The percentages of males and females in the study were 48.0% and 52.0%, respectively. Of all patients, 17.0% (Group B) reported known systemic disease, while 83.0% (Group A) reported no specific medical history. There were significant differences between Groups A and B in CBC, coagulation panel, electrolytes, and chemistry panel (P<0.05). In Group A, the results of blood tests that required a change in procedure were identified even though the proportion was very small. Conclusion: Preoperative blood tests for office-based surgery can detect underlying medical conditions that are difficult to identify from patient history alone and can prevent unexpected sequelae. In addition, such tests can result in a more professional treatment process and build patient confidence in the dentist.

골수이형성증후군과 백혈병에서의 p53 변이체의 검출과 isochromosome 17q

김미향,황현용,정석훈,김양수,어완규,박재선,문영희 대한임상병리학회 2000 대한임상병리학회지 Vol.20 No.4

The effects of pentoxifylline and tocopherol in jaw osteomyelitis

Mi Hyun Seo,Mi Young Eo,Hoon Myoung,Soung Min Kim,Jong Ho Lee 대한구강악안면외과학회 2020 대한구강악안면외과학회지 Vol.46 No.1

Objectives: Pentoxifylline (PTX) is a methylxanthine derivative that has been implicated in the pathogenesis of peripheral vessel disease and intermittent lameness. The purpose of this study was to investigate the effect of PTX and tocopherol in patients diagnosed with osteoradionecrosis (ORN), bisphosphonate-related osteonecrosis of the jaw (BRONJ), and chronic osteomyelitis using digital panoramic radiographs. Materials and Methods: This study was performed in 25 patients who were prescribed PTX and tocopherol for treatment of ORN, BRONJ, and chronic osteomyelitis between January 2014 and May 2018 in Seoul National University Dental Hospital. Radiographic densities of the dental panorama were compared prior to starting PTX and tocopherol, at 3 months, and at 6 months after prescription. Radiographic densities were measured using Adobe Photoshop CS6 (Adobe System Inc., USA). Blood sample tests showing the degree of inflammation at the initial visit were considered the baseline and compared with results after 3 to 6 months. Statistical analysis was performed using the Mann-Whitney test and repeated measurement ANOVA using IBM SPSS 23.0 (IBM Corp., USA). Results: Eight patients were diagnosed with ORN, nine patients with BRONJ, and the other 8 patients with chronic osteomyelitis. Ten of the 25 patients were men, average age was 66.32±14.39 years, and average duration of medication was 151.8±80.65 days (range, 56-315 days). Statistically significant increases were observed in the changes between 3 and 6 months after prescription (P<0.05). There was no significant difference between ORN, BRONJ, and chronic osteomyelitis. Only erythrocyte sedimentation rate (ESR) was statistically significantly lower than before treatment (P<0.05) among the white blood cell (WBC), ESR, and absolute neutrophil count (ANC). Conclusion: Long-term use of PTX and tocopherol can be an auxiliary method in the treatment of ORN, BRONJ, or chronic osteomyelitis in jaw.