DNA double-strand breaks (DSBs) occur commonly in the all living and in cycling cells. They constitute one of the most severe form of DNA damage, because they affect both strand of DNA. DSBs result in cell death or a genetic alterations including deletion, loss of heterozygosity, translocation, and chromosome loss. DSBs arise from endogenous sources like metabolic products and reactive oxygen, and also exogenous factors like ionizing radiation. Defective DNA DSBs can lead to toxicity and large scale sequence rearrangement that can cause cancer and promote premature aging. There are two major pathways for their repair: homologous recombination(HR) and non-homologous end-joining(NHEJ). The HR pathway is a known“ error-free”repair mechanism, in which a homologous sister chromatid serves as a template. NHEJ, on the other hand, is a“ error-prone”pathway, in which the two termini of the broken DNA molecule are used to form compatible ends that are directly ligated. This review aims to provide a fundamental understanding of how HR and NHEJ pathways operate, cause genome instability, and what kind of genes during the pathways are associated with head and neck cancer.
Purpose: Gelatin-hydroxyapatite nanocomposite is similar to inorganic nanostructure of bone. To make a scaffold with osteoinductivity, bone marrow derived stem cells from rabbit femur were impinged into the nanocomposite. This vitro study was to test osteogenic differentiation of the stem cells in the nanocomposite, which was made by authors. Material & Methods: Gel-HA nanocomposite with 10g of HA, 3 g of Gel has been made by co-precipitation process. Bone marrow was obtained from femur of New Zealand White rabbits and osteogenic differentiation was induced by culturing of the BMSCs in an osteogenic medium. The BMSCs were seeded into the Gel-HA nanocomposite scaffold using a stirring seeding method. The scaffolds with the cells were examined by scanning electron microscopy (SEM), colorimetry assay, biochemical assay with alkaline phosphatase (ALP) diagnostic kit, osteocalcin ELISA kit. Results: Gel-HA nanocomposite scaffolds were fabricated with relatively homogenous microscale pores (20-40μm). The BMSCs were obtained from bone marrow of rabbit femurs and confirmed with flow cytometry, Alizarin red staining. Attachment and proliferation of BMSCs in Gel-HA nanocomposite scaffold could be identified by SEM, ALP activity and osteocalcin content of BMSCs. Conclusion: The Gel-HA nanocomposite scaffold with micropores could be fabricated and could support BMSCs seeding, osteogenic differentiation.
Background In contrast to defects of the mandible and mouth floor region, in the defect of maxilla, the availability of firmly attached oral and nasal mucosal linings is needed. In addition to it, in consider of operation field, operating convenience, and esthetics, reconstruction using prelaminated flap is strongly recommended. Therefore we consider the prelaminated flap through the cases that is reconstructed using prelaminated forearm flap and prelaminated scapular flap. Patients and Methods From 2001 to 2008, in OMFS SNUDH, there were 6 cases that had reconstruction using prelaminated forearm free flap and other 3 cases that had reconstruction using prelaminated scapular flap of maxilla. The average age of patients that were reconstructed using prelaminated forearm free flap was 47.5 years, the average prelaminated period (after 1st operation ~ until 2nd operation) was 51.8 days and the average follow-up period after 2nd operation was 35.3 months. As well, the average age of patients that were reconstructed using prelaminated scapular free flap was 37 years, the average prelaminated period (after 1st operation ~ until 2nd operation) was 57 days and the average follow-up period after 2nd operation was 42.3 months. Results Except 1 case that were reconstructed using prelaminated scapular flap, we could get firmly attached oral and nasal stable skin(mucosal like) lining, more adequate thickness flap than any other flap and improved esthetic and functional results in the other 8 cases that were reconstructed using prelaminated flap. The complications of the prelaminated forearm flap cases were inconvenient swallowing, sputum, limitation of mouth opening and difficult mastication. It came from flap shrinkage of the flap in some aspect, as well as other combined operations such as mass resection or RND. The difficult point of the reconstruction of prelaminated scapular flap was the possibility of vascular damage at preparation of flap in 2nd surgery. The damage could cause the failure of the prelaminated scapular flap. And the skin-lining of the prelaminated flap had limitations, so it is needed to study about the cultured oral epithelium-lining flap instead of the skin-lining flap. Conclusion We considered about advantages, complications and notable things of prelaminated flap through maxillary reconstruction cases using prelaminated forearm flap and prelaminated scapular flap so far. Furthermore, we should go on studying for functional reconstruction of prelaminated fasciomucosal flap using cultured oral epithelium.
Objective: The purpose of this study is to determine the prevalence of sinus disease and abnormalities in patients scheduled for dental implant in maxillary posterior area using cone beam CT. Patients and Method: One hundred five maxillary sinuses in eighty-seven patients who underwent cone beam CT for dental implant in maxillary posterior area were included. Any patients who had previous history of sinus operations were not included. The sinus abnormalities were classified as follows ; normal (membrane thickness 〈2 mm), mucosal thickening (membrane thickness ≥ 2 mm and 〈6 mm), partial opacification (membrane thickness 〉6 mm but not full), full opacification and mucous retention cyst. The relationship between the remaining bone height, sinus symptoms and maxillary sinus abnormality was statistically surveyed. Results: Of 105 maxillary sinuses in 87 patients, 80 (76%) maxillary sinuses showed abnormalities ; 4 of 4 symptomatic patients and 76 of 101 asymptomatic patients. Mucosal thickening was the most common sinus abnormality. Only 3 (4%) of 80 maxillary sinus abnormalities were caused by the odontogenic origin. The prevalence of maxillary sinus abnormalities was higher in the symptomatic group than asymptomatic one (p<0.05). Conclusion: Maxillary sinus abnormalities were very common in the patients who were planning implantation in maxillary posterior areas. This result supports that thorough evaluation for maxillary sinus is recommended When implant treatment is planned for those areas.
Background and Objectives: To determine the anatomic position of the inferior alveolar nerve (IAN) canal in patients with mandibular prognathism using the cone-beam CT (CBCT). Materials and Methods: Fifty rami from 25 patients were evaluated. The images were taken by i-CAT and reconstructed 3-dimensionally using the Simplant 11 program. The linear distances between the IAN canal to the buccal cortex (a, a* and a*), from the IAN canal to the alveolar crest (b and b*) and the anterior margin (b*) and finally the buccal cortical thickness (c, c* and c*) were measured at three reference planes (VP, OP and HP). Results: On the left side, the average distance of a, b and c were 7.12, 15.96 and 3.60 mm on the VP plane, respectively. On the OP, the distance of a*, b* and c* was 6.11, 8.83 and 2.63 mm. For the HP, the distance of a*, b* and c* was 4.84, 10.11 and 2.30 mm. On the right side, the distance of a, b and c, on the VP, was 7.10, 16.13 and 3.42 mm, respectively. On the OP, the distance of a*, b* and c* was 4.77, 8.75 and 2.68 mm. On the HP, the distance of a*, b* and c* was 4.55, 9.84 and 2.38 mm. Regarding the difference between genders, the distance in male’s was longer than female’s on the VP (p=0.019), and was thicker in males than females on the HP (p=0.002). Conclusion: The CBCT data provided accurate information about the location and course of the IAN.
Purpose: This study compared the frequency of postoperative infections in patients for a closed mandibular fracture with that without the postoperative antibiotic prophylaxis. Patients and Methods: 48 patients without any specific medical history were divided into two groups depending on whether or not antibiotics had been applied after the surgery. The 24 patients in group 1 received only a second-generation cephalosporin (Cefotetan®) intravenously from admission to immediate after the surgery. Likewise, 24 patients in group 2 received 1.0g of Cefotetan® twice daily longer than the third day after surgery. The mean (SD) duration of antibiotics administration after surgery was 6.9 (±3.56). The patients were evaluated after surgery for any postoperative infections according to the criteria: purulent drainage from a wound, spontaneous wound dehiscence accompanied by swelling, pain, and fever around the wound. Results: Postoperative infections were encountered in 2 out of 24 patients in group 1, who received antibiotic medication until shortly after surgery, and in 3 out of the 24 patients in group 2, in whom the medication was continued even after the surgery. There was no sig nificant difference in the incidence of postoperative infections between the two groups. Conclusion: From this study, postoperative use of antibiotics seems to be unnecessary with view of the little significance of the factors that could affect the wound infection.
In oral & maxillofacial surgery, careful management is necessary to avoid infection for old aged person or patient with diabetes mellitus(DM). We experienced a 69 years old female patient with DM, who has liver abscess and appendicitis, caused by Klebsiella pneumoniae, was developed into left mid-facial abscess and peritonitis. We report this case along with review of article for we have gained fairly good results in our attempt to resolve the patient’s abscess by means of I & D of the left mid-face and percutaneous catheter drainage of the stomach, supplemented with fluid and antibiotic therapy.
Maxillary sinusitis is an infectious disease which can arise from odontogenic etiology and a maxillary osteomyelitis can spread into the sinus and consequently develop maxillary sinusitis. In this case report, a mid eighty’s lady was diagnosed as BRONJ with maxillary sinusitis as a complication. The patient was managed successfully in collaboration with a endocrinologist. Through serial follow-up of serum CTX, we could decide the timing of surgical intervention.
Lipoma is most common tumor that compromises 4% to 5% of all benign neoplasm, but in oral cavity it is uncommon. In oral cavity, lipoma presents painless, asymptomatic , slow growing, but sometimes it grows to larger size causing deformities, mastication and speech difficulties. While lipoma in commonly affects female patients (68-73%), oral lipoma appears more frequently in male patients. The majority of oral lipoma is seen after the age of forty (uncommon in children). Lipoma of oral cavity and maxillofacial region occurs most commonly in the parotid region, followed by the buccal mucosa, lip, tongue, palate, mouth floor, gingiva in order. A treatment of lesion is surgical excision with recurrence not expected. In this paper we present the case of a patient who has Lipoma in the mouth floor.
Verrucous carcinoma is a distinctive form of low-grade squamous cell carcinoma. The tumor has an exophytic, cauliflower-like appearance, and usually occurs in males and tends to affect individuals over 60 years of age. It typically involves the oral cavity, larynx, esophagus and skin. Most intraoral cases involve the mandibular vestibule, the buccal mucosa and the hard palate. The cause is unknown, but most verrucous carcinomas arise from the oral mucosa in people who chronically use chewing tobacco or snuff. The treatment of oral verrucous carcinoma remains controversial. Whenever possible, surgically total excision and skin or mucosal grafting is recommended. After total excision of huge verrucous carcinoma,instead of dermal or mucosal grafting, we used artificial dermis silicone membrane. We had a good result without recurrence and present this case.