Cathepsins are common and well-characterized lysosomal cysteine proteinases involved in tissue destruction under pathological conditions. A recent immunocytochemical study reported that cathepsins B (CAB) and L (CAL) were localized in the periodontal ligament (PDL) of the rat molar. Further, our laboratory demonstrated that the levels of CAB and CAL in gingival crevicular fluid increased during orthodontic tooth movement. The present study focused on the localization of CAB and CAL during experimental tooth movement as well as participation by these cathepsins in the alteration of the periodontal tissues. Tooth movement was performed with the Waldo method, and the time points used for elastic band extraction were 1, 3, and 7 days after tooth movement. To determine localization of CAB and CAL using immunohistochemical analysis was used. Immunoreactivity for CAB and CAL was detected in osteoclasts and PDL fibroblasts. One day after tooth movement, the PDL fiber arrangement became coarse on both sides, and regressive lesions formed while the degree of staining for CAB and CAL increased in those cells as a whole. However, 3 days after tooth movement, many osteoclasts appeared in the compression and tension sides, and the immunoreactivity of CAB and CAL was increased in osteoclasts and fibroblasts. The present study demonstrated that CAB and CAL could be detected in PDL fibroblasts and osteoclasts and were increased in those cells following experimental tooth movement. Therefore, mechanical stress may be involved in extracellular matrix degradation and bone resorption through the stimulation of cathepsins, which is one of the important factors in the periodontal tissues.

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Adenomatoid odontogenic tumor (AOT), which is hitstopathologically composed of pseudoductal cells intermingled with polygonal cells, is a rare odontogenic lesion. On the other hand, ameloblastoma (AM) which tends to grow slowly is most common odontogenic tumor of the jaws. The aim of this study was to compare with the proliferative activity in epithelium of AOT and AM. In addition, the role of cellular proliferation in the pseudoductal cells and polygonal cells of AOT was immunohistochemically and histochemically investigated using several proliferative markers as follows : Ki-67, PCNA and AgNORs. These labelling indexes were calculated in them. The mean Ki-67 and PCNA labeling indexes in AOT were statistically lower than those in AM (p<0.05). And about AOT, the mean Ki-67 labeling index in pseudoductal cells was statistically higher than that in polygonal cells (p<0.05). The present study showed the difference proliferative activity between pseudoductal cells and polygonal cells might depend on cell differentiation.

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In the current studies, we used frontier molecular orbital theory to understand the coupling reaction of tresyl chloride (Cl-SO₂CH₂CF₃)-activated titanium and fibronectin. Because titanium contains a large number of basic functions, it is impossible to calculate the molecular orbital of titanium. Therefore, we used methanol as model compound for calculations. Semi-empirical determinations of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) for methanol, tresyl chloride, tresylated methanol, and methyl amine were obtained using PM3 Hamiltonian calculations. We found that energy difference between the HOMO of methanol and the LUMO of tresyl chloride (9.004 eV) is smaller than that between the LUMO of methanol and the HOMO of tresyl chloride (15.855 eV). This suggests that the reaction of tresyl chloride and methanol is dominated by the interaction of the HOMO of methanol and LUMO of tresyl chloride. In addition, the energy difference between the LUMO of tresylated methanol and HOMO of methyl amine (8.559 eV) is smaller than that between the LUMO of methanol and HOMO of methyl amine (12.909 eV). Therefore, the nucleophilic reaction of methyl amine towards tresylated methanol proceeds more easily than that of the reaction towards methanol. In conclusion, the tresylation of methanol improves its reactivity towards methyl amine by reducing methanol's LUMO energy levels.

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Background. Plexiform ameloblastoma is more common in younger patients while and the follicular pattern is more frequently seen in older patients. However, factors implicated in determining the microscopic growth pattern of ameloblastoma are unclear.
Methods. A total of 23 cases of ameloblastoma were included in this study and were divided into 2 groups according to age : group A≤15 years (12 cases), and group B≥60 years (11 cases). Each group was assessed for predominant histological pattern (follicular vs. plexiform) and for immunoreactivity with 2 monoclonal antibodies : Ki-67 and CD31. Ki-67 labeling index, intratumor microvessel density (IMVD) and intratumor microvessel area (IMVA) were calculated in each case.
Results. The majority of cases in group A exhibited a plexiform pattern, while the follicular pattern predominated among group B. Ki-67 labeling index, IMVD, and IMVA were significantly higher in group A than in group B. When the 2 histological patterns of ameloblastoma were compared, only IMVD and IMVA were statistically higher in plexiform ameloblastoma.
Conclusions. Our results suggest that angiogenesis could affect the pattern of tumor growth in ameloblastoma. Both angiogenesis and growth pattern were influenced by patient age.

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Transcutaneous immunization is a new method of vaccination that utilizes a topical application of antigen to intact skin for induction of immune responses. In this study, we have assessed the potential for the application of transcutaneous immunization for the development of a novel vaccine- delivery system. When BALB/c mice were immunized with ovalbumin (OVA) by direct application to shaved skin, OVA-specific serum IgG antibody responses were induced ; however, none was induced in saliva. On the other hand, when OVA was given with cholera toxin (CT) as adjuvant, higher levels of OVA-specific serum IgG antibody responses were induced than that of OVA alone. Furthermore, OVA-specific IgG antibody responses were detected in the saliva of mice immunized with OVA plus CT. Antibody-forming cell (AFC) analysis confirmed the antibody titers by revealing significant numbers of OVA-specific IgG AFCs in the spleen and salivary gland. In addition, mononuclear cells from the spleen and cervical lymph nodes of mice immunized with OVA plus CT exhibited significant levels of proliferative responses when restimulated with OVA in vitro. These results indicate that transcutaneous immunization may be an effective vaccine delivery system for the induction of protein antigen-specific antibody responses in the oral cavity.

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In the current studies, we examined the ability of human dental follicle cells (DFCs), dental pulp stem cells (DPSCs), and oral mucosal cells (OMCs) to form dentin by analyzing their expression of the odontoblast-specific genes, dentin sialophosphoprotein (DSPP) and dentin sialoprotein (DSP), and the mineralization-associated genes, alkaline phosphatase (ALP) and dentin matrix protein-1 (DMP-1). Phase contrast microscopy showed that DFCs, DPSCs, and OMCs exhibited spindle-shaped and fibroblastic morphologies. Also, more bone nodules were formed in DFCs than in DPSCs, whereas bone nodules were not found in OMCs. Analysis of gene expression by real-time reverse transcriptase-polymerase chain reaction showed a time-dependent increase in the expression of DSPP in differentiating DFCs and DPSCs, but almost no expression in OMCs. The expression of DSPP in DFCs was approximately 4-fold higher than in DPSCs after 15 days in culture, and, almost 6-fold higher after 27 days. In addition, the expression of DSP, DMP-1 and ALP was observed in both DFCs and DPSCs, with a slow increase until 15 days of differentiation, and, after 21 days, there was a rapid increase in the expression of these genes in DFCs. In contrast, expression of these genes was almost undetectable in OMCs and in undifferentiated DFCs, DPSCs and OMCs. These results suggest that, compared to DPSCs, DFCs have a superior capacity for dentin formation and mineralization and that they may be useful for the regeneration of dentin or tooth tissues using tissue engineering technology.

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A new chemotherapy regimen consisting of intravenous docetaxel (60 mg/m²) and nedaplatin (70 mg/m²) was performed in a 51-year-old patient with unresectable squamous cell carcinoma of the tongue (T4N0M0). After 2 courses of chemotherapy and follow-up irradiation, complete tumor regression was observed (clinical CR). Except for short-term grade 4 neutropenia and mucositis, severe toxicities were not observed. Excision of scar tissue at the tumor site was performed without causing tongue dysfunction, and pathological CR was confirmed. In the present case, DOC/CDGP chemotherapy followed by radiotherapy was effective against locally advanced squamous cell carcinoma of the tongue.

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Oral lichen planus (OLP) is a chronic mucocutaneous disease, well described clinically and histologically, but the etiology remains unknown. Various systemic and/or local predisposing factors have been implicated in the etiopathogenesis of OLP. Saliva and its constituents play an important role in the homeostasis of the oral cavity, and alterations either in its quantity or quality might contribute to various oral diseases and disturbances. In 30 patients with OLP (age range 30-62, mean 52), diagnosis was made on the basis of histopathological and clinical findings. The control group consisted of 28 participants (age range 23-27, mean 24). Each participant collected saliva using the simple method of spitting unstimulated whole saliva into calibrated tubes (0, 1 ml) during a five minute period between 8-11 A.M. Salivary peroxidase levels were determined according to Putter and Becker. Statistical analysis was performed using descriptive statistics, and Student t-test p-values below 0.05 were considered statistically significant. No significant differences between patients with OLP and controls in salivary flow rate as well as in salivary peroxidase levels were found. Our results might indicate that neither salivary flow rate nor salivary peroxidase level contribute to the pathogenesis of OLP.

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The objectives of this study were to observe the surface appearance as well as resin tag formation on acid-etched human enamel using field-emission scanning microscopy (FE-SEM) and to study the effects of saliva contamination and repeat etching. Phosphoric acid etching produced a finely roughened enamel surface with random arrangement of enamel crystals. Dissolution of both enamel prisms and peripheries was observed. FE-SEM observation reveals a large amount of remaining contaminated saliva on the etched enamel and subsequently no resin tag formation. Repeat etching after saliva contamination incompletely removed the contaminated saliva and produced less density of resin tags. The results of SEM observation may provide an explanation for the results of shear bond strengths ; that is, a large amount of contaminated saliva remaining on the etched enamel surface and incomplete removal of contaminated saliva after repeat etching result in the decrease of shear bond strength of 4-META/MMA-TBB resin to enamel.

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The purpose of this study was to evaluate the differences in oral stereognosis ability between dentate individuals and denture wearers with and without cleft lip and palate before and after chewing. Fifty subjects were divided into three groups : Group 1 was 20 dentate subjects (ages between 21-49 years), Group 2 was 20 denture wearers without cleft lip and palate (ages between 42-70 years), and Group 3 was 10 denture wearers with cleft lip and palate (ages between 24-60 years). All complete dentures had a mean use time of three months, good retention, clinical stability, and supporting tissues with no signs of inflammation. The subjects were asked to recognize six different test pieces. Pieces were inserted and manipulated between the maxillary and mandibular central incisors, before and after chewing a slice of raw carrot. Only correct responses received one point. Data analysis on oral stereognosis levels before and after chewing was conducted with statistical software, with a level of significance of p<0.05. Statistically significant differences in the oral stereognosis levels were observed before and after chewing only in the dentate group. Oral stereognosis levels of dentate subjects were higher than those observed in edentulous subjects. Oral stereognosis levels of denture wearers with cleft lip and palate were lower than those observed in edentulous subjects without clefts ; chewing did not influence the oral stereognosis levels in edentulous patients. Further studies are necessary to evaluate the effects of repeated chewing on the oral stereognosis levels.

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