The purpose of the present study was to investigate whether apoptosis related proteins (Bax and caspase-3) are present in the masseter muscle of ten-week-old male mdx mice, the animal model for human Duchenne muscular dystrophy, and to infer the lytic mechanism of the masseter muscle fiber. Immunohistochemistry was performed toward fresh frozen sections using the antibodies of Bax, active caspase-3 and single stranded DNA (ssDNA). As a result, the localizations of Bax and active caspase-3 and ssDNA positive areas were confirmed in lytic muscle fibers. It was suggested that the mitochondria dependent program cell death advanced about these areas. However, Bax localizations were detected in regenerated muscle fibers with central nucleus and nerve fibers in a perimysium. The relationship between these Bax localizations and cell death of the muscle fibers was not clear.

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To analyze the prevalence of postoperative maxillary cyst (POMC), we reviewed cysts occurring in the maxillary and mandibular jaw bones from the files of Tokyo Medical and Dental University from 1976 to 2001. Among 7,105 cases of intrabony jaw cysts, 1,141 cases (16%) were POMC. The high incidence of POMC among intrabone jaw cysts was also reported by other institutions or hospitals in Japan. Collaborating pathologists in other countries examined the prevalence of the lesion in their universities or hospitals and it was acknowledged to be low. This study suggests a significantly higher prevalence of POMC among the Japanese.

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Tobacco-smoking and betel quid chewing habits are highly prevalent in Southeast Asia including Myanmar. In this study, clinico-pathological parameters of oral lesions and alterations in p53-expression were investigated. Forty-nine cases of leukoplakia (n=20), oral submucous fibrosis (OSMF) (n=15) and oral lichen planus (OLP) (n=14) were investigated for p53-expression by immunohistochemistry. Male predilection was seen with leukoplakia and OSMF. Total mean age was 48.3 for leukoplakia, 37.9 for OSMF and 42.2 for OLP. Buccal mucosa was the most common site. Betel quid chewing and smoking habits were significantly related with leukoplakia and OSMF (P=0.000) and influenced in p53-expression (P=0.000). Grade of dysplasia was strongly associated with p53-positivity and expression pattern in basal and suprabasal layer (P=0.004; Crude OR=895% CI=1.9-34.5). This study suggests that alterations of p53-expression are important indicators for prediction of malignant transformation in betel quid chewing and tobacco-smoking associated pre-malignant lesions.

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To evaluate the expression of cell cycle associated protein p53, mdm2 and p21 in betel quid chewing and tobacco smoking (BQT) associated oral squamous cell carcinoma (OSCC) in Bangladesh, we examined 107 tissue specimens by immunohistochemical method. High expression of p53, mdm2 and p21 were found in 75%, 71% and 65% of BQT associated OSCCs, respectively. Overexpression of p53 and mdm2 were found to be significantly high in BQT habit factor (p= 0.007 and 0.016 respectively). Significant correlation was also found between p53⁺/mdm2⁺ (p= 0.0001) and p53⁺/p21⁺ (p= 0.0001). Discordant mdm2⁺/p53^- and p21⁺/p53^- phenotypes were observed in 11 (10%) and 17 (16%) cases, respectively, suggesting a p53-independent role for mdm2 and p21 in the pathogenesis of a subset of OSCCs. In conclusion, betel quid chewing and tobacco smoking may have carcinogenic effect on oral epithelium in Bangladesh. Overexpression of mdm2 and p21 may occur in a p53-dependent or independent manner.

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Patients with severe rheumatoid arthritis of the temporomandibular joints (TMJ) often present with degenerative changes in the condylar process of the mandible and a reduction of the mandibular ramus, which leads to osteoarthrosis of the TMJ and resultant anterior open bite and retrognathism. This report documens the treatment of this type of problem with a new technique combining intermaxillary traction and arthroscopic disc suture / fixation. The intermaxillary traction of the upper and lower dentition was performed on two patients in order to bring the lower jaw back to its original position and improve occlusion. The disc was then sutured and fixed to the posterior wall of the upper joint cavity under arthroscopy to protect the condylar surface in the enlarged articular space. Both patients showed good postoperative stability after the remodeling of the condylar process of the mandible. As well as improved occlusion.

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