Diabetes mellitus (DM) is a typical life style related disease, in which hyperglycemia is caused by an absolute defect (type 1 DM) or relative defect (type 2 DM) of insulin. Specifically, type 2 DM is considered a life style related disease. DM is known to cause a capillary vessel disorder due to the hyperglycemia and often brings about delayed wound healing ; however, the mechanism behind this delayed wound healing is uncertain and the effect of laser irradiation using a mouse model is insufficient. Thus, this paper studies histopathological and immunohistochemical changes using the db/db mouse model in order to investigate the wound healing mechanism in type 2 DM as well as the biological effects of wound healing by low-energy laser irradiation. This DM model mice (db/db) were compared with a normal mice (m+/m+). The different levels of inflammatory cell infiltration in the wound site, capillary dilatation and regeneration, and proliferation of fibroblasts and collagen fibers were observed over time, and delayed wound healing was studied histopathologically. Moreover, db/db of laser irradiation was compared with db/db of non laser irradiation, finding capillary dilatation and regeneration, the proliferation of fibroblasts and collagen fibers prominent. Mast cells seen by metachromasia in toluidine blue pH 2.5 staining were observed in the dermis around the margin on the wound site of m+/m+ and db/db of non laser irradiation, capillary dilatation and regeneration, and proliferation of the fibroblasts and collagen fibers surroundings. The number of mast cells over time was lower in db/db of non laser irradiation than in m+/m+, however, more degranulation was seen in db/db of laser irradiation than in db/db of non laser irradiation. According to immunohistochemical findings, HSP70 was positively immunoreactive in neutrophils, macrophages, vascular endothelial cells, fibroblasts and epidermis. Moreover, the appearance of HSP70 was lower in db/db of non laser irradiation than in m+/m+. The appearance level of HSP70 in vascular endothelial cells was higher in db/db of laser irradiation than in db/db of non laser irradiation. NOS2 kept positively high in vascular endothelial cells continuously until 7 days post-operatively in db/db of the non laser irradiation compared with m+/m+. On the other hand, the level of NOS2 was low in macrophages and vascular endothelial cells in db/db of laser irradiation. Moreover, while the appearance of FGF2 was identified on 2 days in neutrophils in m+/m+, it was seen by 5 days in db/db of non laser irradiation, suggesting a delayed appearance time. The positive appearance of FGF2 was high in vascular endothelial cells and fibroblasts in db/db of laser irradiation. These findings suggest a delayed wound healing process in db/db of non laser irradiation by the decrease in the mast cell number and mast cell degranulation, decreased expression of HSP70 and FGF2, and increased expression of NOS2. It is speculated that low-energy laser irradiation improves the above findings and delayed wound healing process in db/db of non laser irradiation.

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A new mouthguard material, polyolefin, was recently developed. To date, no studies have compared ethylene vinyl acetate (EVA) and polyolefin mouthguards. The aim of this study was to evaluate the physical properties of polyolefin, relative to those of EVA. Two polyolefin materials, hard and regular, were used, in addition to EVA. Hardness, tensile strength, tear strength, elongation, and water absorption were analyzed, as well as the adhesive strength of the materials in laminated mouthguards. Hard polyolefin (MG-H) and EVA were significantly harder than regular polyolefin (MG-R) (p<0.01). Regular polyolefin had significantly lower tensile and tear strengths than MG-H and EVA (p<0.01), while MG-H had significantly higher tensile and tear strengths than EVA (p<0.01). Both polyolefin materials had significantly lower water absorption and higher adhesive strength than EVA (p<0.01). In this study, polyolefin exhibited satisfactory physical properties when compared with EVA. This suggests that polyolefin is suitable for use as a mouthguard material.

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The purposes of this study were to investigate the facial changes by two-jaw surgery for mandibular prognathism accompanying maxillary hypoplasia and skeletal open bite, and to design a regression model that predicts the soft tissue profile changes after two-jaw surgery. Fourteen cases diagnosed as mandibular prognathism accompanying maxillary hypoplasia and skeletal open bite at the Nihon University Hospital, School of Dentistry at Matsudo were studied. The surgical methods used were Le Fort type I osteotomy for the maxilla and sagittal split ramus osteotomy for the mandible. Angle measurements showed significant differences in SNA, ANB, FA, FD and MPA (p<0.01), and significant difference in SNB (p<0.05). In horizontal distances, PTV-L1, PTV-Id, PTV-B, PTV-Pog and PTV-Me changed significantly (p<0.01). In vertical distances, a significant change in N-Me was observed (p<0.05). In horizontal distances, significant changes were observed in PTV-Li and PTV-Spog (p<0.01), and in PTV-St (p<0.05). In vertical distances, significant changes in PTV-St and PTV-Li were observed (p<0.05). No significant changes in cheek line were observed. For the horizontal lip and chin position, the multiple correlation coefficients R ranged from 0.89 to 0.95, and for the horizontal position of the cheek line, the multiple correlation coefficients R ranged from 0.65 to 0.84, indicating a high precision of the prediction equations obtained in this study. In conclusion, the result of this study indicates that the prediction equation for lips and chin has a high precision and can be applied to predict soft tissue profile in two-jaw surgery.

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Non-Hodgkin's lymphomas are a diverse and complex group of malignant tumours arising from cells of the lymphoreticular system, usually B-lymphocytes. Rarely seen in the oral cavity, extranodal non-Hodgkin's lymphoma is now seen with some frequency in patients with HIV. Oral HIV-related lymphomas exhibit an aggressive course and can mimic other oral tumours and infections, which makes early recognition and diagnosis difficult. We present a case of non-Hodgkin's lymphoma on the mandibular gingiva as the first manifestation of HIV infection in a young patient, and review the literature.

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We describe herein the case of an 80-year-old man who suffered sialolithiasis and chronic sialadenitis of the minor salivary gland. Sialolithiasis occurs as a result of the presence of sialoliths in salivary ducts or parenchyma of salivary glands, but is rare in the minor salivary glands. The clinical and pathological findings of our case are also examined with reference to sialolithiasis in minor salivary glands described in the literature. Epithelial metaplasia, lobular inflammation and parenchymal atrophy were common findings. Follow-up examination was good. There was no recurrence of the buccal swelling. The pathological findings indicated that chronic inflammation and squamous cell metaplasia could be related to the etiological factors of this lesion or due to aging. The present case is the first instance of sialolithiasis of the buccal gland to be reported in Japan.

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Oral health is closely related to the condition of competitive athletes and those engaged in other sports. Dental diseases can lower performance by interfering with concentration during games and practice sessions. This should not be overlooked when providing team support. We began providing dental examinations, counseling on dental treatment and disease prevention, and the fabrication of custom-made mouthguards to motorsport drivers and staff members. In doing so, we found the following. 1. Dental examination and oral hygiene instructions are necessary parts of a medical examination. In only a few cases in this report, full cooperation from a team could be obtained. It is therefore necessary to provide further education on the importance of dental support. 2. Active education of motorsport competitors is necessary with regard to preventing odontogenic attrition, reducing defatigation of masticatory muscles, minimizing oral trauma, and fabricating custom-made mouthguards for racers. In addition to mouthguards, dental check-ups are particularly important.

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