Laparoscopy instrument requires blood vessel ligator to prevent blood leakage. Clip ligation device is widely used to prevent blood loss and secure surgical vision by using blood vessel ligator. However, in order to properly install the clip to the vessel ligator and ligate the blood vessel by the ligation machine, the device is properly operated and the parts constituting the jaw areas should be ensuring sufficient strength and rigidity during the operating. Therefore, the clip binding forces were calculated through a dynamic model of the blood vessel ligator. As a result, the force satisfies the target value of 8.5 N or more regardless of the grip force positions. And structural analysis was carried out to find out the maximum resistance force at the tip of the inner shaft. The maximum load was about 45.6 N, which sufficiently satisfies the development target of 40.0 N or higher.

Lymphoma, which accounts for 3.5% of all oral cancers, is further divided into Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). NHL accounts for 96% of lymphomas, and diffuse large B-cell lymphoma (DLBCL) is the most common subtype accounting for 32% of NHL. In the oral cavity, extra-nodal non-Hodgkin's lymphoma may develop in the dentoalveolar region of the maxilla or mandible. It can also mimic inflammatory lesions that occur around periodontal tissues, such as periapical granuloma and chronic osteomyelitis. Misdiagnosis of jaw lymphoma can delay appropriate treatments and worsen the prognosis. Therefore, to avoid delay in diagnosis, clinicians should identify the possible malignancy based on unusual symptoms, clinical findings, radiographic examinations, and histopathological evaluation. We present two cases of DLBCL in the right posterior mandible of a 64-year-old man who was initially misdiagnosed as acute apical abscess and in the right posterior maxilla of an 81-year-old woman who was initially misdiagnosed as chronic periodontitis. These cases demonstrate that it is important for both pathologists and clinicians to consider malignant lesions such as lymphomas in the differential diagnosis of apical radiolucency.

This study was planned to evaluate the efficacy of surgical treatment in stage 2 medication related osteonecrosis of jaw(MRONJ) patients. Retrospective analysis was performed about patients who were treated with medication related osteonecrosis of jaw from 2015 to 2017. 25 Patients were treated by a single surgeon at the Department of Oral Surgery, Dental Hospital, Pusan National University. The treatment methods they received were conservative or surgical. The results of treatment were classified as "fail" and "success" and the prognosis according to the treatment method was compared. Conservative treatment 14.29% (2 cases), sequestrectomy 64.29% (9 cases) and saucerization 21.43% (3 cases) were performed in the MRONJ group, and 2 treatment failures were encountered after conservative treatment and 1 after saucerization. Surgical treatment resulted in better outcomes in stage 2 MRONJ patients. Furthermore, treatments were deemed successful when surrounding necrotic bone containing sequestrum was reliably removed. Therefore, this study suggests that the treatment of "stage 2" MRONJ should actively consider surgical treatment.

The dentigerous cyst is defined as a cyst that originates by the separation of the follicle from around the crown of an unerupted tooth. This is the most common type of developmental odontogenic cyst, making up about 20% of all epithelium-lined cysts of the jaws. Large dentigerous cysts are uncommon, but some cases are large cysts. The usual treatment for a dentigerous cyst is careful enucleation of the cyst together with removal of the unerupted tooth. Large dentigerous cysts also may be treated by decompression. This permits decompression of the cyst, with a resulting reduction in the size of the bone defect. The cyst can then be enucleated at a later date with a less extensive surgical procedure and important structures such as teeth and the inferior alveolar nerve can be preserved. These cases are large dentigerous cysts treated by decompression. Less extensive surgical procedures were used and some teeth were preserved.

악기를 능숙하게 연주하기 위해 구조와 기능을 아는 것은 매우 중요하다. 사람은 목소리를 악 기로 사용하지만, 목소리를 내는 기관은 만질 수 없고 눈에 보이지 않기 때문에 접근하기 어렵 다. 그래서 해부학적으로 접근해야만 구조를 알게 된다. 우리가 몸 안의 기관을 해부학적으로 정확하게 인식하는 것이 운동기능 향상에 영향을 준다. 이것을 ‘운동 감각’을 통해 증명한다. 공명과 턱관절 및 근육의 정의와 기능을 알고 ‘턱 근육의 올바른 사용’이 발성의 ‘공명’에 미치는 영향을 알았을 때 우리는 가창에 필요한 운동기능을 훈련할 수 있게 된다. 이 훈련을 통 해 턱 근육과 발성 기관을 인지하여 가창했을 때 부정적인 주변 환경, 심리상태와 상관없이 좋은 공명의 가창을 할 수 있도록 훈련할 수 있다. 또한, 추상적인 표현의 교수법 등으로 교사의 경험 이 학생에게 제대로 전달되지 못하는 경우가 많다. 발성 기관의 해부학적 접근을 통해 교사와 학생의 거리를 좁힐 수 있는 직접적이고 효과적인 교수법을 제시한다.

Osteonecrosis is defined as non-vital bone tissue as a result of abnormal process of osseous healing, and is caused by several reasons such as infection, radiation, and medication. Osteomyelitis, osteoradionecrosis, and medication related osteonecrosis of the jaws (MRONJ) which have necrotic bone in common are confused clinically due to similar symptoms and radiographic findings, and are difficult to diagnose definitively. Because each disease represents a separate clinical progress and requires a different treatment approach, it is very important to distinguish each disease. The aim of this study was to analyze the histopathologic features of osteomyelitis, osteoradionecrosis, MRONJ and to understand their different pathogenesis.

29-year-old female with chronic renal failure and a history of hemodialysis during 10 years showed localized jaw enlargement in the anterior mandible. She also revealed increased serum PTH level, osteosclerosis in her skull base and facial bone, chronic pain in the both knee joint, and gastrointestinal disorder which are symptoms of renal osteodystrophy. The patient was diagnosed hyperparathyroidism associated with chronic renal failure. Parathyroidectomy was performed, however, serum PTH level increased again after the parathyroidectomy, the affected area of the mandible was enlarged as the serum PTH level increased. The enlarged area seemed like as peripheral lesion clinically. We reported a case of localized jaw enlargement as oral manifestation in renal osteodystrophy.

Amelobl astic carcinoma(AC) is a maJignant coun terpart of ameloblastoma. histologically characteri zed by amelobJastomatolls feature with obviollS cytologic a typi a . AC is a r are malignant tumor with poten t iaJ of metastasis‘ asssllmed to occur far less tha n 1% of ameloblastoma . Nearly 80% of ACs have been reported to occur in the mandibJ e. The allthors reviewed 5 cases of AC in Department of Oral PathoJogy. SeouJ National University from 2005 to 2007 clini copathologically according to age, sex. location and clinical findings. They occllrred at the age from 46 to 75 years wi th average age of 60 Four cases occurred in male and 1 in female‘ showing prediJ ection for ma le‘ While four cases occu rred in the maxilla , including 3 cases in the maxillary molar area and 1 in the maxiJJ a ry premola l‘ a rea, only 1 case occurred in the mandibJe. AC showing predorninance in the maxilla over t he ma ndible in our cases in contrast to other case reviews. Three patients presented painful large oral lllcer at the time of admi ssion, a nd other 2 patients presented swol1en mass around the gingivae and alveoJar bone While the clini cal impression of 3 patients were ma lignant tllmor, other 2 patients were amelboJastoma and nicotine stomatitis. The dllration of symptoms before final diagnosis has ranged from 4 months to 2 years Radiogr a phicalJy they showed poorly demarcated radiolucent lesion with irreg비 ar bony destruction. Resected tumors were measured as 6.0X4.5x4.0cm‘ 0‘ 7xO.5xO.3cm, 5.0 x 4.5 X5.0cm. 0.8xO.6 XO.5cm, and 5cm diametel mass respecti vely. Microscopically lymph node metastasis was confirmed in 1 case, but not in others . The tumors showed basic histologic featu re of ameloblastoma with apparent cytologic atypia sllch as pleomol‘ phism‘ hyper chromatism and atypical ffiJ tOSIS Individua l neoplastic cells displayed wide va riations from case to case‘ showing c lear cells with faint PAS positive granules‘ isolated round cells with abundant cytoplasm. s quamoid ceJls and polygonaJ cell s . [mmunohis toc hemical survey was done in 2 cases. all of which showed positivity to pan-cytoker atin a ntibody and p53 a ntibody‘ but negativity to HMB-45, S-100, and SMA One case recurred twice during 2 yeal's after surgery. But 3 cases showed no evidence of recurrence and metastas is. lt seems to us t hat AC have the potential of metastasis and reCllrrence.