About 5 % of odontogenic keratocysts (OKC) arise in association with basal cell nevus syndrome (BCNS), a genetical disorder caused by aberrant function of patched1 (ptch1) gene. Ptch1 is a receptor of Sonic hedgehog (Shh), whose signaling plays a role in proliferation of developing odontogenic epithelium. OKC specimens from five BCNS patients were examined immunohistochemically for expression of Ptch1, Ptch2, Shh and CyclinD1. Ptch1 and Shh staining was distinct in the lining epithelium, and 20-50 % of basal/suprabasal cells were positive for CyclinD1. Ptch2 staining was as weak as none. Loss of heterozygosity (LOH) in ptch1 and ptch2 loci was probed; in which one case showed no LOH for ptch1 while three cases showed no LOH for ptch2. Co-expression of Shh and its receptor in OKC epithelium implicates that autocrine or paracrine activation of hedgehog signaling within the lining cells is involved in genesis of OKC associated with BCNS.

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Three human cell lines, NB-1, NT-1 and NT-2 from the tongue and buccal squamous cell carcinoma (SCC), were established and characterized. The cells were polygonal in shape and grew in typical cobblestone pattern with cytokeratin expression in the cytoplasm. Colony forming efficiency in collagen gel was 20-98% and the cell lines were hypotetraploid. The cell motility assay demonstrated that the migration activity of NT-1 cells was higher than that of NB-1 and NT-2 cells. NT-2 cells secreted a large amount of IL-6 and IL-8. Xenografted cells formed tumors in all nude mice examined. Metastasis to the cervical lymph nodes was demonstrated in some mice that received cell inoculation in the tongue. There was no remarkable difference in three cell lines as to the tumor cell proliferation activity in terms of PCNA immunohistochemical staining.

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To clarify the mechanism involved in age-related fibrotic changes, we investigated immunohistochemical expression of HSP47, type I procollagen, and type I collagen in the salivary glands of Mongolian gerbils aged 1 to 63 months old. Positive reactions to HSP47 and type I procollagen were seen in the fibroblasts and striated duct cells in each glands. Increased fibrous connective tissue and adipose tissue were presented mostly in the parotid gland, less in the submandibular and sublingual gland. The number of fibroblasts expressing HSP47 and type I procollagen increased with age. In the sublingual gland, fibroblast with positive reaction to HSP47 and type I procollagen were observed in the adult and old group. These results indicate that increase of fibroblasts with intracellular HSP47 might be significantly involved in fibrotic changes of salivary gland in aging. Possibility of synthesis and excretion of collagen by striated duct is suggested as well.

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The tumor suppressor gene p53 is important in cell cycle regulation and induction of apoptosis. Accumulation of p53 protein due to mutation of the p53 gene has been shown to enhance chemoresistance in various malignant tumors. This study was performed to clarify whether p53 expression correlates with response to chemotherapy in oral squamous cell carcinoma (OSCC). We retrospectively reviewed 26 cases of OSCC treated with chemotherapy using a combination of cisplatin and 5-FU (CF therapy). Expression of p53 was examined in pretreatment biopsy specimens using the streptoavidin-biotin peroxidase method with antigen retrieval. The p53-labeling index (LI) was 28.64 ± 34.97% (range 0-100%) in patients for whom therapy was effective, and 74.13 ± 35.68% (range 0-100%) in patients for whom therapy was ineffective. The difference in p53-LI values between the two groups was significant (p<0.021, Mann-Whitney U test). Thus, p53 expression was associated with sensitivity of OSCC to CF therapy.

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We report here a rare case of primary B-cell lymphoma in the submandibular lymph node that spread to the deep cervical lymph nodes of a 55-year-old man. The lymphoma was accompanied by a chronic sialadenitis of the submandibular gland with a cluster of lymphocytes and exhibited a typical pattern of follicular lymphoma. Immunohistochemical and flow cytometric analysis showed the presence of CD10, CD19 and bcl-2 on lymphoid cells in the follicles, which confirmed that this nodal lesion was follicular lymphoma. The manner of spreading of the lymphoma indicated that the primary lesion originated in the submandibular region. In spite of a diagnosis of Grade 1, the lesion had spread to the deep cervical lymph nodes. A possible relationship between sialadenitis and the initiation of lymphoma was not detected by the present examinations.

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We performed arthroscopic suturing of the articular disc followed by surgical correction of jaw deformity in patients with dysfunction of the temporomandibular joint when jaw deformity was suspected as an underlying cause of temporomandibular disorders. A representative case is presented. A 25-year-old female was treated with arthroscopic disc suturing designed to increase the effective thickness of an anteriorly displaced disc. Sagittal splitting of the mandibular ramus was subsequently performed to improve occlusion. At present, 11 years 8 months after surgery, both facial asymmetry and malocclusion remain improved and temporomandibular joint symptoms have been alleviated.

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