The oral cavity is rich in blood flow, which can cause excessive bleeding. Excessive bleeding in oral cavity is rare, but if the cause of the bleeding is not found, the patient's life may be at risk. Therefore, in the case of excessive bleeding, the dentist should consider the cause and provide appropriate first treatment. Hydrofluoric acid is widely used as a material for pre-treatment of ceramics before oral restoration for prosthetics and conservative dentistry. Since hydrofluoric acid is very reactive, when it comes into contact with tissues, even very diluted 0.1% hydrofluoric acid can cause very painful 2-3 degree burns, which heal very slowly. Negative reactions and even deaths of hydrofluoric acid have been reported in other fields, but there are very few case reports of complications related to hydrofluoric acid in the dental field. In this article, we report a case of excessive gingival bleeding after restorative treatment and discuss the effects of hydrofluoric acid on oral soft tissues and blood vessels and its prevention

Mucormycosis is an aggressive opportunistic fungal infection that can be found in the oral cavity. The fungus usually affects the immunocompromised patients and tends to invade and block blood vessels, resulting in significant tissue necrosis and invasive mucormycosis. However, a non-invasive form of mucormycosis is mostly asymptomatic and found accidentally in the immunocompetent normal hosts, manifested by localized overgrowth of the fungus. Here, we report a rare case of asymptomatic non-invasive mucormycosis of the mandible that was incidentally diagnosed in wide resection specimen of liver transplant patient who had previously underwent surgery of excision and simultaneous alloplastic bone graft due to mandibular ameloblastoma. Histopathological examination of the specimen revealed that there was neither vasculitis nor tissue necrosis, but numerous fungal hyphae were located only within the alloplastic graft materials in decalcified tissue sections. Awareness of the possibility of life-threatening mucormycosis in immunocompromised patients should be emphasized because it can be inactive or reactivated depending on the immune state of patients.

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.

This study were to perform for verifying the activation areas in the human's brain during mastication by using functional-MRI (f-MRI) device on the basis of hypothesis regarding anatomical-physiological parts of brain processing the information of motor and sensory function, and to perform further more for a providing basic provisional foundation about diagnosis, treatment and prognosis of abnormal occlusion as applying functional MRI. Generally healthy 10 volunteers who have a normal occlusion were selected. The half of members of volunteers was female. Age distributions were approximately alike. Before taking a f-MRI, sufficient practice was carried out as strict standards and made volunteers be not sensible to sweet taste of gum through chewing gum for 30 minutes before taking a f-MRI. Functional images for all volunteers were firstly obtained, and then anatomical images were next. The functional images consisted of echo-planar image volumes which were sensitive to BOLD (blood oxygenation level-dependent) contrast in axial orientation. The volume covered the whole brain with a 64×64 matrix and 42 slices. Images with 64 volumes were acquired under periodic mastication. The orofacial sensorimotor cortex was primary responsible cerebral part during mastication and insula. And also supplementary motor area and cerebellum in brain were intimately connected with mastication. Other numerous anatomical parts of brain were activated in each volunteer during mastication, but there was no statistical significance in this experiment. Differences according to gender and age were no significance in this study. The f-MRI device showed the accurate and detailed image in activation area of brain through valuable device. It suggested that f-MRI might be helpful to establish the basis of funtional standard occlusion depend on activation area of brain.

The rise of medical knowledge and awareness of the importance of dental and stomatognathic system increase the patients who visit dental emergency room. The chief complaints of patients who visited the emergency room varies from a pain, trauma, hemorrhag. The purpose of this study was to classify dental emergency patients by chief complaint and to analyze in indiviual group and to provide more effective emergency dental care. This study was carried out with 1129 patients visiting emergency room of the dankook university dental hospital from 7/2011 to 6/2012. Dental emergency patients was classified trauma, pain, hemorrhage group by chief complaint and studied mothly, the day of the week, time, age distribution and cause of the individual group. The chief complaint of visiting emergency room were trauma 660 people (58.5%), pain 347 people (30.7%), hemorrhage 96 (8.5%), other 26 patients (2.3%). The monthly distribution was observed in May (12.8%), March (10.5%), September (10.2%). The trauma patients were frequent in the spring and early summer but painful patients visited in September (12.7%) and May (11.8%) in March (11.2%). The peak age group was 20 to 29 years(20.9%), followed by 0 to 9 years(19.4%), 40 to 49years (15.2%,). In trauma group the peak age was under the age of 10 (31.7%), followed by 10 to 19 years (18.8%), 20 to 29 years (17.1%) . However, in pain group, peak age was 20 to 29 years (26.8%) followed by 40 to 49 years(21.3%), 30 to 39 years (19.6 %). The most common cause of trauma were subluxation(16.5%), laceration13.7%), uncomplicated crown fracture(12.05%) and in pain group was pulpal origin(46.1%), followed by periodontal origin( 20.7%), post op pain(8.9%). Undefined pain or neuralgia were 7.9%. The most common cause of hemorrhage was post extraction( 66.7%), post operation(16.7%), spontaneous bleeding due to periodontitis(12.5%). In conclusion, the trauma, pain were different in monthly distribution and the peak age of patients. Dental emergeny doctor should understand pattern of indiviual emergency group and perform proper diagnosis and treatment for more effective emergency care.

The population of patients with antiplatelet treatment is expanding globally with the rising prevalence of cardiovascular disease and increasing use of percutaneous coronoary interventions. While antiplatelet agents have revolutionized the management of atherosclerotic disease and its thromotic complications, the potential of bleeding remains an inherent risk. Dentists are more likely to stop antiplatelet therapy before dental extraction because they think that the patient is at high risk for bleeding. However stopping or altering antiplatelet therapy may expose such patients to the risk of a thromboembolic event such as thromboembolism, myocardial infarction, or cerebrovascular accidents particulary in patients wirh drug-eluting stent. In this study, we report 3cases that were perfomed dental extraction in patients receiving single or dual antiplatelet therapy without immediate and late postextraction bleeding and reviewed the literature on dental extraction in patients receiving antiplatelet therapy. We concluded that dental extractions may be safely performed in patients receiving single or dual antiplatelet therapy when appropriate local hemostatic measures are taken, thus averting thrombotic risk of temporary antiplatelet discontinuation

Odontogenic cysts are classified into inflammatory and developmental origins. The most common representative inflammatory cyst is periapical cyst and the most common representative developmental cyst is dentigerous cyst and cyst which show character of tumor is odontogenic keratocyst and cyst of which cystic epithleial lining cells transform to ameloblastoma is unicystic ameloblastoma. About ten years ago p63 protein that are closely related to p53 protein was found. Authors studied about comparative pattern of expression of p63 protein in periapical cyst, dentigerous cysts, odontogenic kertocysts and unicystic ameloblastomas. Authors selected 10 cases for every four types of cyst and performed immunohistochemical staining by using monoclonal antibody about p63 protein, LSAB(labelled streptoavidin biotin) reactant and HRP(horse raish peroxidase) system. Positive cells about p63 protein were expressed at basal layer of cystic lining epithelium in periapical cysts, odontogenic keratocysts and unicytic ameloblastomas. On the contrary, in dentigerous cysts positive cells were expressed at surfce layer. Perapical cysts and odontogenic keratocysts showed significantly high values of labelling indices.(periapical cyst:72.49%, odontogenic keratocyst:64.72%, dentigerous cyst:8.94%, unicystic ameloblastoma: 5.25%) Odontogenic keratocyst showed the most strong staining intensity and the second was periapical cyst, the third was dentigerous cyst, and lastly unicystic ameloblastoma. Conclusively cause that the positive cells appeared at surface layer in dentigerous cyst reflected the position of epithelium to the enamel, and labelling indices of p63 protein were closely related to proliferative capacity and intensity of expression closely related to the labelling index and thus labelling index was also closely related to proliferative capacity of cystic lining epithelium.

Ameloblastomas are benign odontogenic tumor and the most common neoplasm in jaws and they have locally invasive property and high recurrence rate. Four typical subtypes ameloblastomas are plexiform, follicular, granular cell and acanthomatous type, but their developmental states during tumorigenesis are uncertain. And thus authors studied about developing states of four types of ameloblastomas by immunohistochemical staining for cytokeratin 8/18 which was an intermediate filament of epithelial cell origin and for vimentin which was an intermediate filament of mesenchymal cell origin, and then by comparative analyses of the results. Authors selected seven cases for every four types of ameloblastomas, and then performed immunohistochemcial staining for cytkeratin 8/18 and vimentin to all selected specimen by using monoclonal antibodies about cytoleratin 8/18 and vimentin, LSAB(Labelled StreptoAvidin Biotin) reactant and HRP(Horse Radish Peroxidase) system. Labelling indices of cytokeratin 8/18 of plexiform and follicular types of ameloblastomas were significantly high values in the group of ameloblast-like cells and labelling indices of cytokeratin 8/18 of all types of ameloblastoma were high values in the group of transformed cells, but their differences were not significant. Labelling index of vimentin of plexiform ameloblastoma was significantly high value in the group of ameloblast-like cells and others showed comparatively lower values. Labelling index of vimentin of granular cell type of ameloblastoma in the group of transformed cells was significantly high value and others showed comparatively lower values. Consequently the most primitive form of ameloblastoma was plexiform, and more differenciated form was follicular type and granular cell type and acanthomatous type were most differenciated form of ameloblastomas

World Health Organization(WHO) revised the classification of neoplasms and other tumours related to odontogenic apparatus in 1992. The aim of this study was to classify the odontogenic tumors of Korean according to the WHO Histologic classification. A total of 271 cases were reviewed for the study which were diagnosed as odontogenic tumors at the department of Oral Pathology, Yonsei University College of Dentistry for the period from Jan. 1997 to March 2003. Clinical and pathology reports were reviewed & radiographic feature were examined. The following results were obtained : 1. Among 271 cases, 269 cases(99.3%) were diagnosed as benign odontogenic tumors, and the remaining 2 cases(0.7%) were malignant tumors, which were diagnosed as odontogenic ghost cell carcinoma and squamous cell carcinoma ex odontogenic cyst. 2. Four cases were not able to classify into the WHO classification. All of them were belonged to mixed odontogenic tumors; two cases of adenomatoid odontogenic tumor with calcifying epithelial odontogenic tumor, one case of adenomatoid odontogenic tumor with odontoma, odotogenic cyst and one case of ameloblastoma with immature odontoma. 3. The most frequent odontogenic tumour was odontoma(45.2%), followed by ameloblastoma (29.2%), odontogenic fibroma(9.2%) 4. One case of atypical amelobalstoma and one case of calcifying odontogenic cyst with ameloblastic fibroma were not able to subclassify histologically. 5. Male to female ratio of odontogenic tumors was 1.2:!. Odontogenic tumors mainly occured in the first and second decade, occurred twice as much as in the mandible than in the maxilla 6. The odontogenic tumors was discovered by routine oral x-ray examination, whereas the chief complaint of ameloblastoma were swelling, pain. 7. Ameloblastoma, adenomatoid odontogenic tumor, calcifying odontogenic cyst and odontoma were related to the impacted teeth and tooth displacement. The root resorption was frequently observed in ameloblastoma and calcifying odontogenic cyst.