Thermally induced bone necrosis during implant surgery: 3 case reports

Thermally induced bone necrosis during implant surgery is a rare phenomenon and a potential contributing factor to implant failure. The frictional heat generated at the time of surgery causes a certain degree of necrosis of the surrounding differentiated and undifferentiated cells. The bone necrosis occurred in the mandible in all three cases, leading to a soft tissue lesion and pain. In each case, radiolucent areas appeared in the middle and apical portions of the implant 4 weeks after surgery. Thermally induced bone necrosis did not improve following systemic antibiotic medication, necessitating surgical treatment. The nonintegrated implants were removed, and meticulous debridement of dead bone and granulation tissue was performed. Then, new implants were implanted along with the placement of autogenous and xenogenic bone covered with a collagen membrane. No further complications occurred after re-operation. The radiolucencies around the new implants gradually resolved entirely, and the soft tissue lesions healed successfully. At 4-5 months after reoperation, implant loading was initiated and the implant-supported restorations have been functioning. The aim of this case report is to present the successful clinical treatment of three cases suspected to be caused by thermally induced bone necrosis after implant drilling.

The usefulness of immediate implantation using Bio-Oss. and Bio-Gide.in ITI. implant system

Clinical study of mandibular fracture of children

Case report of Neurofibroma

Study of the relationship between the indication rod of stent on implant CT and the real path of implant fixture insertion considering residual ridge / 대한구강악안면방사선학회지

PURPOSE: To assess the relationship between the direction of the indicating rod of the radiographic stent for ideal prosthetic design and the actual possible path of implant fixture placement when residual ridge resorption is considered. MATERIALS AND METHODS: The study materials consisted of 326 implant sites (male 214 cases and female 112 cases) from a total of 106 patients (male 65 patients and female 41 patients) who desired implant prostheses. Computed tomography of patients were taken and reformatted using ToothPix (R) software. Bony defects, bony sclerosis, the change of the direction of indicating rod, and root proximity of the adjacent teeth were examined on the CT-derived images. RESULTS: The rate of the irregular crestal cortex was relatively high on premolar and molar area of maxilla. Mandibular molar area showed relatively high rate of focal sclerosis on the area of implant fixture insertion. The position of the indicating rods were relatively acceptable on the molar areas of both jaws. However, the position of the indicating rods should be shifted to buccal side with lingual rotation of the apical end on maxillary anterior teeth and premolar area. CONCLUSION: Clinically determined rod direction and position of the indicating rod for implant placement was not always acceptable for insertion according to the reformatted CT images. The pre-operative treatment plan for implant should be determined carefully, considering the state of the alveolar bone using the reformatted CT images.

Effect of irradiation on cell cycle, cell death and expression of its related proteins in normal human oral keratinocytes / 대한구강악안면방사선학회지

PURPOSE: To investigate the radiosensitivity of the normal human oral keratinocytes (NHOK), and the effect of irradiation on cell cycle and protein expression. MATERIALS AND METHODS: To evaluate the radiosensitivity of NHOK, the number of colonies and cells were counted after irradiation and the SF2 (survival fraction at 2 Gy) value, and the cell survival curve fitted on a linear-quadratic model were obtained. LDH analysis was carried out to evaluate the necrosis of NHOK at 1, 2, 3, and 4 days after 2, 10, and 20 Gy irradiation. Cell cycle arrest and the induction of apoptosis were analyzed using flow cytometry at 1, 2, 3, and 4 days after 2, 10, and 20 Gy irradiation. Finally, proteins related cell cycle arrest and apoptosis were analysed by Western blot. RESULTS: The number of survived cell was significantly decreased in a dose-dependent manner. The cell survival curve showed SF2, alpha, and beta values to be 0.568, 0.209, and 0.020 respectively. At 20 Gy irradiated cells showed higher optical density than the control group. After irradiation, apoptosis was not observed but G2 arrest was observed in the NHOK cells. 1 day after 10 Gy irradiation, the expression of p53 remained unchanged, the p21 (WAF1/Cip1) increased and the mdm2 decreased. The expression of bax, bcl-2, cyclin B1, and cyclin D remained unchanged. CONCLUSION: These results indicate that NHOK responds to irradiation by G2 arrest, which is possibly mediated by the expression of p21 WAF1/Cip1, and that cell necrosis occurs by high dose irradiation.

Ranula in an infant

A comparative study on the accuracy of digital subtraction radiography according to the aquisition methods of reconstructed images / 대한구강악안면방사선학회지

PURPOSE: To compare the accuracy of digital subtraction images acquired by two different methods different in positioning four reference points for geometrical standardization. MATERIALS AND METHODS: A total of 36 digital radiographic images of 6 volunteers were taken at the areas of the incisor, premolar, and molar of both the maxilla and mandible using the Digora system. Each image was moved 4 mm vertically and horizontally. Four oral and maxillofacial radiologists performed digital subtraction radiography between the paired images before and after movement using Emago (Oral Diagnostic Systems, Amsterdam, The Netherlands) and Sunny (Biomedisys Co., Seoul, Korea). The standard deviation of the internal gray value in Region of Interest (ROI) was statistically analyzed between the two programs using the paired t-test. RESULTS: The standard deviation of pixel gray values from the digital subtraction images using the Sunny program were lower than that of the Emago program (p<0.05). All observers showed significant differences between each other when the Sunny program was used (p<0.05), but one observer showed a significantly higher score than other observers when they used Emago (p<0.05). The standard deviations of premolar area from both Sunny and Emago programs were significantly higher than those of anterior and molar regions (p<0.05). CONCLUSION: The subtracted images using the Sunny program were more accurate and sensitive than those taken using the Emago program.

Radiologic assessment of bone healing after orthognathic surgery using fractal analysis / 대한구강악안면방사선학회지

PURPOSE: To evaluate the radiographic change of operation sites after orthognathic surgery using the digital image processing and fractal analysis. MATERIALS AND METHODS: A series of panoramic radiographs of thirty-five randomly selected patients who had undergone mandibular orthognathic surgery (bilateral sagittal split ramus osteotomy) without clinical complication for osseous healing, were taken. The panoramic radiographs of each selected patient were taken at pre-operation (stage 0), 1 or 2 days after operation (stage 1), 1 month after operation (stage 2), 6 months after operation (stage 3), and 12 months after operation (stage 4). The radiographs were digitized at 600 dpi, 8 bit, and 256 gray levels. The region of interest, centered on the bony gap area of the operation site, was selected and the fractal dimension was calculated by using the tile-counting method. The mean values and standard deviations of fractal dimension for each stage were calculated and the differences among stage 0, 1, 2, 3, and 4 were evaluated through repeated measures of the ANOVA and paired t-test. RESULTS: The mean values and standard deviations of the fractal dimensions obtained from stage 0, 1, 2, 3, and 4 were 1.658 +/-0.048, 1.580 +/-0.050, 1.607 +/-0.046, 1.624 +/-0.049, and 1.641 +/-0.061, respectively. The fractal dimensions from stage 1 to stage 4 were shown to have a tendency to increase (p<0.05). CONCLUSION: The tendency of the fractal dimesion to increase relative to healing time may be a useful means of evaluating post-operative bony healing of the osteotomy site.

Cervicofacial Necrotizing Fasciitis: Case Report

The study of soft tissue changes of upper and lower lips following bssro in skeletal class iii malocclusion patients

Muscle weakness and vision disorder following open reduction of both condylar fracture: Case Report

TREATMENT OF PLEOMORPHIC ADENOMA ON PALATE: A CASE REPORT

Radiation-induced apoptosis, necrosis and G2 arrest in Fadu and Hep2 cells / 대한구강악안면방사선학회지

PURPOSE: Radiation damage is produced and viable cell number is reduced. We need to know the type of cell death by the ionizing radiation and the amount and duration of cell cycle arrest. In this study, we want to identified the main cause of the cellular damage in the oral cancer cells and normal keratinocytes with clinical useful radiation dosage. MATERIALS AND METHODS: Human gingival tissue specimens obtained from healthy volunteers were used for primary culture of the normal human oral keratinocytes(NHOK). Primary NHOK were prepared from separated epithelial tissue and maintained in keratinocyte growth medium containing 0.15 mM calcium and a supplementary growth factor bullet kit as described previously. Fadu and Hep-2 cell lines were obtained from KCLB. Cells were irradiated in a (137)Cs gamma-irradiator at the dose of 10 Gy. The dose rate was 5.38 Gy/min. The necrotic cell death was examined with Lactate Dehydrogenase(LDH) activity in the culture medium. Every 4 day after irradiation, LDH activities were read and compared control group. Cell cycle phase distribution and preG1-incidence after radiation was analyzed by flow cytometry using Propidium Iodine(PI) staining. Cell cycle analysis were carried out with a FAC Star plus flowcytometry(FACS, Becton Dickinson, USA) and DNA histograms were processed with CELLFIT software(Becton Dickinson, USA). RESULTS: LDH activity increased in all of the experimental cells by the times. This pattern could be seen in the non-irradiated cells, and there was no difference between the non-irradiated cells and irradiated cells. We detected an induction of apoptosis after irradiation with a single dose of 10 Gy. The maximal rate of apoptosis ranged from 4.0% to 8.o% 4 days after irradiation. In all experimental cells, we detected G2/M arrest after irradiation with a single dose of 10 Gy. Yet there were differences in the number of G2/M arrested cells. The maximal rate of the G2/M ranges from 60.0% to 80.0% 24h after irradiation. There is no significant changes on the rate of the G0/G1 phase. CONCLUSION: Radiation sensitivity was not related with necrosis but cell cycle arrest and apoptosis. These data suggested that more arrested cell is correlated with more apoptosis.

Diagnostic imaging of recurred mandibular ameloblastoma with large soft tissue involvement / 대한구강악안면방사선학회지

An uncommon case of a patient with recurrent mandibular ameloblastoma involving various adjacent soft tissues is presented with plain film radiography, computed tomography and magnetic resonance imaging(MRI) and bone scan. The tumor involved mandible and eroded several bones including foramen ovale. This case shows that although an ameloblastoma primarily affect mandible, exact radiographic evaluation of tumor extent will assist the surgeon in the progress of rational approaches to the management of ameloblastoma.

The Effect of Irradiation on the Expression of PCNA and Apoptosis Induction during the DMBA Induced Carcinogenesis in Hamster Buccal Pouch / 대한구강악안면방사선학회지

PURPOSE: This study was carried out to investigate the effect of irradiation on the expression of proliferating cell nuclear antigen (PCNA) and apoptosis induction during the carcinogenesis in hamster buccal pouch. MATERIALS AND METHODS: Three months old Syrian golden hamsters were divided into control and 2 experimental groups. Hamsters in control group were left untreated on buccal pouchs. Twenty four hamsters were treated with 0.5% DMBA tri-weekly on the right buccal pouch. Forty eight hamsters were treated with 0.5% DMBA tri-weekly and irradiated with the dose of 5 Gy and 10 Gy at 6, 9, 12, 15 weeks after DMBA application. Resected buccal pouches were sectioned and examined for potential expression pattern of PCNA and apoptosis. RESULTS: The PCNA index was increased with the stages of buccal pouch epithelium carcinogenesis except the hyperplasia stage in control group (p<0.05). The irradiation did not effect on the PCNA index in the dysplasia and the carcinoma in situ stage, but in the hyperplasia stage, the PCNA index was increased with 10 Gy radiation and decreased in the carcinoma stage (p<0.05). The apoptotic index was significantly decreased from the carcinoma in situ stage and the lowest in the carcinoma stage. The apoptotic index was significantly decreased in the hyperplasia and dysplasia stage with the 5 Gy irradiation and significantly increased only in the carcinoma stage with the 10 Gy irradiation (p<0.05). CONCLUSION: The PCNA and apoptotic index were varied according to the irradiation period and dosage in each carcinogenesis stage.

A CLINICAL STUDY ON THE MIDFACE FRACTURE

With the increase of industrialization, leisures, sports activities and traffic, the risk of trauma has increased markedly. Midfacial bones are relatively common sites of trauma, and are difficult sites of correct reduction and reconstruction, because midface is composed of mostly thin cortical bone surrounding cavities filled with either air or fat with discrete areas of bony condensation. A clinical study on 208 patients with midfacial bone fracture who visited Sanggye Paik Hospital during 5 years(1990~1995) was done by analyzing sex, age, cause, fracture site, treatment method, complication and involvement of other body part, etc. The results obtained were as follows : 1. The occurrence was more frequent in male than in female with ratio of 2.7 : 1 and most frequently in twenties. 2. Traffic accident was the most common cause of midface fractures. 3. Zygoma was the most frequently occurred site(50%) of midface fractures. 4. Simple fracture(75%) was more frequently occurred than compound fracture(25%). 5. As treatment method, open reduction(76.4%) was used more frequently than closed reduction(23.6%) 6. Generally, operations are done in 5 days after admission(59.1%), and intermaxillary fixation was done in 78.4% of cases. 7. Teeth and alveolar bone damages were occurred in 32.2% of cases. 8. Other injuries that were related to midface fracture occurred in 63.3% of cases. 9. Post-operative complications occurred in 9% of cases.

Case Reports Of Osteosarcoma In Mandible

Sarcoma is a malignant tumor originated from bone, cartilage, fat tissue, nerve, blood vessel, bone marrow, endothelium, etc. and for this reason it exhibits considerable variation not only clinical but histologic appearance. Osteosarcoma occurs chiefly in young persons and in patients older than 40 years it is usually associated with Paget's disease, irradiated bone, multiple hereditary exostosis or polyostotoc fibrous dysplasia and sometimes with preceding trauma. Radiographically it is divided into three forms: an osteoblastic or sclerosing type, an osteolytic type, and mixed type. Histologically it is divided into osteoblastic type, chondroblastic type, fibroblastic type. The treatment of osteosarcoma is radical excision, combined chemotherapy but the prognosis is poor and overall 5-year survival rate is 20-40%. We present two different type sarcomas of 22-year-old male and 56-year-old male patients which we performed surgical excision, combined chemotherapy and radiation therapy.

Mucoepidermoid carcinoma of the palate

A comparison of the diagnostic ability between waters' radiograph and computed tomography in the diagnosis of midf acial fracture / 대한구강악안면방사선학회지

This study was intended to compare the diagnostic ability between Waters' radiograph and CT in the diagnosis of mi dfacial fracture. The study group included 44 patients(male:32, female:12, age range:16-74 yeards old) with facial injur y who underwent surgery. Waters' radiograph and both axial and coronal scanning were performed before surgery, Three oral raiologists and thre e non-oral radiologist interpreted 44 waters' radiographs and 88 CT in three ways: 1) interpretation using waters' radi ograph only, 2) interpretation using CT only, 3) interpretation using Waters' radiograph and CT. The interpretation sites were confined to the walls of maxillary sinus; anterior, posterior, medial, lateral and superior wall. ROC curves were made with the findings during surery as a gold standard except the posterior wall, where the joint evaluation of Waters' radiograph and CT by othe three oral raiologists was used. ROC areas were compared according to the interpreting methods, the interpretation sites, and groups (R group ; oral r adiologist group, N group ; non-oral radiologist group). The obtained results were as followed : 1. The diagnostic ability of CT only and Waters' radiograph and CT was higher than Waters' radiograph only in b oth groups(P 2. Generally, the diagnostic ability for the lateral antral wall was the highest and that for the posterior antral wall was the lowest in both groups(P<0.05) 3. In R gruop, for the anterior antral wall the diagnostic ability using CT only was increased but for the medial, late ral and superior antral walls the diagnostic ability was increased in only using Waters' radiograph and CT. 4. In N group, for the anterior and medial walls the diagnostic ability using CT only was increased, But for the poster ior, lateral and superior antral walls there were no difference among three interpreting methods. 5. The diagnostic ability of R group was higher than N group in all interpreting methods.